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authorAlex Crichton <alex@alexcrichton.com>2014-10-14 21:57:50 -0700
committerAlex Crichton <alex@alexcrichton.com>2014-10-19 12:59:40 -0700
commitfb169d5543c84e11038ba2d07b538ec88fb49ca6 (patch)
tree252d6fd6dffe26a06e39f735275979b247f40302 /src/libnum
parentc121cbab35c9ff9ba133c578976a4ec35c011bcf (diff)
Remove a number of deprecated crates
All of these crates have been deprecated for some time and properly live in the
rust-lang organization as cargo-based crates.

To update your code, depend on the rust-lang/foo repository via cargo.

[breaking-change]
Diffstat (limited to 'src/libnum')
-rw-r--r--src/libnum/bigint.rs2961
-rw-r--r--src/libnum/complex.rs379
-rw-r--r--src/libnum/integer.rs507
-rw-r--r--src/libnum/lib.rs73
-rw-r--r--src/libnum/rational.rs803
5 files changed, 0 insertions, 4723 deletions
diff --git a/src/libnum/bigint.rs b/src/libnum/bigint.rs
deleted file mode 100644
index e52d62a040b..00000000000
--- a/src/libnum/bigint.rs
+++ /dev/null
@@ -1,2961 +0,0 @@
-// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! A Big integer (signed version: `BigInt`, unsigned version: `BigUint`).
-//!
-//! A `BigUint` is represented as an array of `BigDigit`s.
-//! A `BigInt` is a combination of `BigUint` and `Sign`.
-//!
-//! Common numerical operations are overloaded, so we can treat them
-//! the same way we treat other numbers.
-//!
-//! ## Example
-//!
-//! ```rust
-//! # #![allow(deprecated)]
-//! use num::bigint::BigUint;
-//! use std::num::{Zero, One};
-//! use std::mem::replace;
-//!
-//! // Calculate large fibonacci numbers.
-//! fn fib(n: uint) -> BigUint {
-//!     let mut f0: BigUint = Zero::zero();
-//!     let mut f1: BigUint = One::one();
-//!     for _ in range(0, n) {
-//!         let f2 = f0 + f1;
-//!         // This is a low cost way of swapping f0 with f1 and f1 with f2.
-//!         f0 = replace(&mut f1, f2);
-//!     }
-//!     f0
-//! }
-//!
-//! // This is a very large number.
-//! println!("fib(1000) = {}", fib(1000));
-//! ```
-//!
-//! It's easy to generate large random numbers:
-//!
-//! ```rust
-//! # #![allow(deprecated)]
-//! use num::bigint::{ToBigInt, RandBigInt};
-//! use std::rand;
-//!
-//! let mut rng = rand::task_rng();
-//! let a = rng.gen_bigint(1000u);
-//!
-//! let low = -10000i.to_bigint().unwrap();
-//! let high = 10000i.to_bigint().unwrap();
-//! let b = rng.gen_bigint_range(&low, &high);
-//!
-//! // Probably an even larger number.
-//! println!("{}", a * b);
-//! ```
-
-use Integer;
-use rand::Rng;
-
-use std::{cmp, fmt, hash};
-use std::default::Default;
-use std::from_str::FromStr;
-use std::num::CheckedDiv;
-use std::num::{ToPrimitive, FromPrimitive};
-use std::num::{Zero, One, ToStrRadix, FromStrRadix};
-use std::string::String;
-use std::{uint, i64, u64};
-
-/// A `BigDigit` is a `BigUint`'s composing element.
-pub type BigDigit = u32;
-
-/// A `DoubleBigDigit` is the internal type used to do the computations.  Its
-/// size is the double of the size of `BigDigit`.
-pub type DoubleBigDigit = u64;
-
-pub const ZERO_BIG_DIGIT: BigDigit = 0;
-static ZERO_VEC: [BigDigit, ..1] = [ZERO_BIG_DIGIT];
-
-#[allow(non_snake_case)]
-pub mod BigDigit {
-    use super::BigDigit;
-    use super::DoubleBigDigit;
-
-    // `DoubleBigDigit` size dependent
-    #[allow(non_uppercase_statics)]
-    pub const bits: uint = 32;
-
-    #[allow(non_uppercase_statics)]
-    pub const base: DoubleBigDigit = 1 << bits;
-    #[allow(non_uppercase_statics)]
-    static lo_mask: DoubleBigDigit = (-1 as DoubleBigDigit) >> bits;
-
-    #[inline]
-    fn get_hi(n: DoubleBigDigit) -> BigDigit { (n >> bits) as BigDigit }
-    #[inline]
-    fn get_lo(n: DoubleBigDigit) -> BigDigit { (n & lo_mask) as BigDigit }
-
-    /// Split one `DoubleBigDigit` into two `BigDigit`s.
-    #[inline]
-    pub fn from_doublebigdigit(n: DoubleBigDigit) -> (BigDigit, BigDigit) {
-        (get_hi(n), get_lo(n))
-    }
-
-    /// Join two `BigDigit`s into one `DoubleBigDigit`
-    #[inline]
-    pub fn to_doublebigdigit(hi: BigDigit, lo: BigDigit) -> DoubleBigDigit {
-        (lo as DoubleBigDigit) | ((hi as DoubleBigDigit) << bits)
-    }
-}
-
-/// A big unsigned integer type.
-///
-/// A `BigUint`-typed value `BigUint { data: vec!(a, b, c) }` represents a number
-/// `(a + b * BigDigit::base + c * BigDigit::base^2)`.
-#[deriving(Clone)]
-pub struct BigUint {
-    data: Vec<BigDigit>
-}
-
-impl PartialEq for BigUint {
-    #[inline]
-    fn eq(&self, other: &BigUint) -> bool {
-        match self.cmp(other) { Equal => true, _ => false }
-    }
-}
-impl Eq for BigUint {}
-
-impl PartialOrd for BigUint {
-    #[inline]
-    fn partial_cmp(&self, other: &BigUint) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for BigUint {
-    #[inline]
-    fn cmp(&self, other: &BigUint) -> Ordering {
-        let (s_len, o_len) = (self.data.len(), other.data.len());
-        if s_len < o_len { return Less; }
-        if s_len > o_len { return Greater;  }
-
-        for (&self_i, &other_i) in self.data.iter().rev().zip(other.data.iter().rev()) {
-            if self_i < other_i { return Less; }
-            if self_i > other_i { return Greater; }
-        }
-        return Equal;
-    }
-}
-
-impl Default for BigUint {
-    #[inline]
-    fn default() -> BigUint { Zero::zero() }
-}
-
-impl<S: hash::Writer> hash::Hash<S> for BigUint {
-    fn hash(&self, state: &mut S) {
-        // hash 0 in case it's all 0's
-        0u32.hash(state);
-
-        let mut found_first_value = false;
-        for elem in self.data.iter().rev() {
-            // don't hash any leading 0's, they shouldn't affect the hash
-            if found_first_value || *elem != 0 {
-                found_first_value = true;
-                elem.hash(state);
-            }
-        }
-    }
-}
-
-impl fmt::Show for BigUint {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.to_str_radix(10))
-    }
-}
-
-impl FromStr for BigUint {
-    #[inline]
-    fn from_str(s: &str) -> Option<BigUint> {
-        FromStrRadix::from_str_radix(s, 10)
-    }
-}
-
-impl Num for BigUint {}
-
-impl BitAnd<BigUint, BigUint> for BigUint {
-    fn bitand(&self, other: &BigUint) -> BigUint {
-        BigUint::new(self.data.iter().zip(other.data.iter()).map(|(ai, bi)| *ai & *bi).collect())
-    }
-}
-
-impl BitOr<BigUint, BigUint> for BigUint {
-    fn bitor(&self, other: &BigUint) -> BigUint {
-        let zeros = ZERO_VEC.iter().cycle();
-        let (a, b) = if self.data.len() > other.data.len() { (self, other) } else { (other, self) };
-        let ored = a.data.iter().zip(b.data.iter().chain(zeros)).map(
-            |(ai, bi)| *ai | *bi
-        ).collect();
-        return BigUint::new(ored);
-    }
-}
-
-impl BitXor<BigUint, BigUint> for BigUint {
-    fn bitxor(&self, other: &BigUint) -> BigUint {
-        let zeros = ZERO_VEC.iter().cycle();
-        let (a, b) = if self.data.len() > other.data.len() { (self, other) } else { (other, self) };
-        let xored = a.data.iter().zip(b.data.iter().chain(zeros)).map(
-            |(ai, bi)| *ai ^ *bi
-        ).collect();
-        return BigUint::new(xored);
-    }
-}
-
-impl Shl<uint, BigUint> for BigUint {
-    #[inline]
-    fn shl(&self, rhs: &uint) -> BigUint {
-        let n_unit = *rhs / BigDigit::bits;
-        let n_bits = *rhs % BigDigit::bits;
-        return self.shl_unit(n_unit).shl_bits(n_bits);
-    }
-}
-
-impl Shr<uint, BigUint> for BigUint {
-    #[inline]
-    fn shr(&self, rhs: &uint) -> BigUint {
-        let n_unit = *rhs / BigDigit::bits;
-        let n_bits = *rhs % BigDigit::bits;
-        return self.shr_unit(n_unit).shr_bits(n_bits);
-    }
-}
-
-impl Zero for BigUint {
-    #[inline]
-    fn zero() -> BigUint { BigUint::new(Vec::new()) }
-
-    #[inline]
-    fn is_zero(&self) -> bool { self.data.is_empty() }
-}
-
-impl One for BigUint {
-    #[inline]
-    fn one() -> BigUint { BigUint::new(vec!(1)) }
-}
-
-impl Unsigned for BigUint {}
-
-impl Add<BigUint, BigUint> for BigUint {
-    fn add(&self, other: &BigUint) -> BigUint {
-        let zeros = ZERO_VEC.iter().cycle();
-        let (a, b) = if self.data.len() > other.data.len() { (self, other) } else { (other, self) };
-
-        let mut carry = 0;
-        let mut sum: Vec<BigDigit> =  a.data.iter().zip(b.data.iter().chain(zeros)).map(|(ai, bi)| {
-            let (hi, lo) = BigDigit::from_doublebigdigit(
-                (*ai as DoubleBigDigit) + (*bi as DoubleBigDigit) + (carry as DoubleBigDigit));
-            carry = hi;
-            lo
-        }).collect();
-        if carry != 0 { sum.push(carry); }
-        return BigUint::new(sum);
-    }
-}
-
-impl Sub<BigUint, BigUint> for BigUint {
-    fn sub(&self, other: &BigUint) -> BigUint {
-        let new_len = cmp::max(self.data.len(), other.data.len());
-        let zeros = ZERO_VEC.iter().cycle();
-        let (a, b) = (self.data.iter().chain(zeros.clone()), other.data.iter().chain(zeros));
-
-        let mut borrow = 0i;
-        let diff: Vec<BigDigit> =  a.take(new_len).zip(b).map(|(ai, bi)| {
-            let (hi, lo) = BigDigit::from_doublebigdigit(
-                BigDigit::base
-                    + (*ai as DoubleBigDigit)
-                    - (*bi as DoubleBigDigit)
-                    - (borrow as DoubleBigDigit)
-            );
-            /*
-            hi * (base) + lo == 1*(base) + ai - bi - borrow
-            => ai - bi - borrow < 0 <=> hi == 0
-            */
-            borrow = if hi == 0 { 1 } else { 0 };
-            lo
-        }).collect();
-
-        assert!(borrow == 0,
-                "Cannot subtract other from self because other is larger than self.");
-        return BigUint::new(diff);
-    }
-}
-
-impl Mul<BigUint, BigUint> for BigUint {
-    fn mul(&self, other: &BigUint) -> BigUint {
-        if self.is_zero() || other.is_zero() { return Zero::zero(); }
-
-        let (s_len, o_len) = (self.data.len(), other.data.len());
-        if s_len == 1 { return mul_digit(other, self.data.as_slice()[0]);  }
-        if o_len == 1 { return mul_digit(self,  other.data.as_slice()[0]); }
-
-        // Using Karatsuba multiplication
-        // (a1 * base + a0) * (b1 * base + b0)
-        // = a1*b1 * base^2 +
-        //   (a1*b1 + a0*b0 - (a1-b0)*(b1-a0)) * base +
-        //   a0*b0
-        let half_len = cmp::max(s_len, o_len) / 2;
-        let (s_hi, s_lo) = cut_at(self,  half_len);
-        let (o_hi, o_lo) = cut_at(other, half_len);
-
-        let ll = s_lo * o_lo;
-        let hh = s_hi * o_hi;
-        let mm = {
-            let (s1, n1) = sub_sign(s_hi, s_lo);
-            let (s2, n2) = sub_sign(o_hi, o_lo);
-            match (s1, s2) {
-                (Equal, _) | (_, Equal) => hh + ll,
-                (Less, Greater) | (Greater, Less) => hh + ll + (n1 * n2),
-                (Less, Less) | (Greater, Greater) => hh + ll - (n1 * n2)
-            }
-        };
-
-        return ll + mm.shl_unit(half_len) + hh.shl_unit(half_len * 2);
-
-
-        fn mul_digit(a: &BigUint, n: BigDigit) -> BigUint {
-            if n == 0 { return Zero::zero(); }
-            if n == 1 { return (*a).clone(); }
-
-            let mut carry = 0;
-            let mut prod: Vec<BigDigit> = a.data.iter().map(|ai| {
-                let (hi, lo) = BigDigit::from_doublebigdigit(
-                    (*ai as DoubleBigDigit) * (n as DoubleBigDigit) + (carry as DoubleBigDigit)
-                );
-                carry = hi;
-                lo
-            }).collect();
-            if carry != 0 { prod.push(carry); }
-            return BigUint::new(prod);
-        }
-
-        #[inline]
-        fn cut_at(a: &BigUint, n: uint) -> (BigUint, BigUint) {
-            let mid = cmp::min(a.data.len(), n);
-            return (BigUint::from_slice(a.data.slice(mid, a.data.len())),
-                    BigUint::from_slice(a.data.slice(0, mid)));
-        }
-
-        #[inline]
-        fn sub_sign(a: BigUint, b: BigUint) -> (Ordering, BigUint) {
-            match a.cmp(&b) {
-                Less    => (Less,    b - a),
-                Greater => (Greater, a - b),
-                _       => (Equal,   Zero::zero())
-            }
-        }
-    }
-}
-
-impl Div<BigUint, BigUint> for BigUint {
-    #[inline]
-    fn div(&self, other: &BigUint) -> BigUint {
-        let (q, _) = self.div_rem(other);
-        return q;
-    }
-}
-
-impl Rem<BigUint, BigUint> for BigUint {
-    #[inline]
-    fn rem(&self, other: &BigUint) -> BigUint {
-        let (_, r) = self.div_rem(other);
-        return r;
-    }
-}
-
-impl Neg<BigUint> for BigUint {
-    #[inline]
-    fn neg(&self) -> BigUint { fail!() }
-}
-
-impl CheckedAdd for BigUint {
-    #[inline]
-    fn checked_add(&self, v: &BigUint) -> Option<BigUint> {
-        return Some(self.add(v));
-    }
-}
-
-impl CheckedSub for BigUint {
-    #[inline]
-    fn checked_sub(&self, v: &BigUint) -> Option<BigUint> {
-        if *self < *v {
-            return None;
-        }
-        return Some(self.sub(v));
-    }
-}
-
-impl CheckedMul for BigUint {
-    #[inline]
-    fn checked_mul(&self, v: &BigUint) -> Option<BigUint> {
-        return Some(self.mul(v));
-    }
-}
-
-impl CheckedDiv for BigUint {
-    #[inline]
-    fn checked_div(&self, v: &BigUint) -> Option<BigUint> {
-        if v.is_zero() {
-            return None;
-        }
-        return Some(self.div(v));
-    }
-}
-
-impl Integer for BigUint {
-    #[inline]
-    fn div_rem(&self, other: &BigUint) -> (BigUint, BigUint) {
-        self.div_mod_floor(other)
-    }
-
-    #[inline]
-    fn div_floor(&self, other: &BigUint) -> BigUint {
-        let (d, _) = self.div_mod_floor(other);
-        return d;
-    }
-
-    #[inline]
-    fn mod_floor(&self, other: &BigUint) -> BigUint {
-        let (_, m) = self.div_mod_floor(other);
-        return m;
-    }
-
-    fn div_mod_floor(&self, other: &BigUint) -> (BigUint, BigUint) {
-        if other.is_zero() { fail!() }
-        if self.is_zero() { return (Zero::zero(), Zero::zero()); }
-        if *other == One::one() { return ((*self).clone(), Zero::zero()); }
-
-        match self.cmp(other) {
-            Less    => return (Zero::zero(), (*self).clone()),
-            Equal   => return (One::one(), Zero::zero()),
-            Greater => {} // Do nothing
-        }
-
-        let mut shift = 0;
-        let mut n = *other.data.last().unwrap();
-        while n < (1 << BigDigit::bits - 2) {
-            n <<= 1;
-            shift += 1;
-        }
-        assert!(shift < BigDigit::bits);
-        let (d, m) = div_mod_floor_inner(self << shift, other << shift);
-        return (d, m >> shift);
-
-
-        fn div_mod_floor_inner(a: BigUint, b: BigUint) -> (BigUint, BigUint) {
-            let mut m = a;
-            let mut d: BigUint = Zero::zero();
-            let mut n = 1;
-            while m >= b {
-                let (d0, d_unit, b_unit) = div_estimate(&m, &b, n);
-                let mut d0 = d0;
-                let mut prod = b * d0;
-                while prod > m {
-                    // FIXME(#5992): assignment operator overloads
-                    // d0 -= d_unit
-                    d0   = d0 - d_unit;
-                    // FIXME(#5992): assignment operator overloads
-                    // prod -= b_unit;
-                    prod = prod - b_unit
-                }
-                if d0.is_zero() {
-                    n = 2;
-                    continue;
-                }
-                n = 1;
-                // FIXME(#5992): assignment operator overloads
-                // d += d0;
-                d = d + d0;
-                // FIXME(#5992): assignment operator overloads
-                // m -= prod;
-                m = m - prod;
-            }
-            return (d, m);
-        }
-
-
-        fn div_estimate(a: &BigUint, b: &BigUint, n: uint)
-            -> (BigUint, BigUint, BigUint) {
-            if a.data.len() < n {
-                return (Zero::zero(), Zero::zero(), (*a).clone());
-            }
-
-            let an = a.data.tailn(a.data.len() - n);
-            let bn = *b.data.last().unwrap();
-            let mut d = Vec::with_capacity(an.len());
-            let mut carry = 0;
-            for elt in an.iter().rev() {
-                let ai = BigDigit::to_doublebigdigit(carry, *elt);
-                let di = ai / (bn as DoubleBigDigit);
-                assert!(di < BigDigit::base);
-                carry = (ai % (bn as DoubleBigDigit)) as BigDigit;
-                d.push(di as BigDigit)
-            }
-            d.reverse();
-
-            let shift = (a.data.len() - an.len()) - (b.data.len() - 1);
-            if shift == 0 {
-                return (BigUint::new(d), One::one(), (*b).clone());
-            }
-            let one: BigUint = One::one();
-            return (BigUint::new(d).shl_unit(shift),
-                    one.shl_unit(shift),
-                    b.shl_unit(shift));
-        }
-    }
-
-    /// Calculates the Greatest Common Divisor (GCD) of the number and `other`.
-    ///
-    /// The result is always positive.
-    #[inline]
-    fn gcd(&self, other: &BigUint) -> BigUint {
-        // Use Euclid's algorithm
-        let mut m = (*self).clone();
-        let mut n = (*other).clone();
-        while !m.is_zero() {
-            let temp = m;
-            m = n % temp;
-            n = temp;
-        }
-        return n;
-    }
-
-    /// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
-    #[inline]
-    fn lcm(&self, other: &BigUint) -> BigUint { ((*self * *other) / self.gcd(other)) }
-
-    /// Deprecated, use `is_multiple_of` instead.
-    #[deprecated = "function renamed to `is_multiple_of`"]
-    #[inline]
-    fn divides(&self, other: &BigUint) -> bool { return self.is_multiple_of(other); }
-
-    /// Returns `true` if the number is a multiple of `other`.
-    #[inline]
-    fn is_multiple_of(&self, other: &BigUint) -> bool { (*self % *other).is_zero() }
-
-    /// Returns `true` if the number is divisible by `2`.
-    #[inline]
-    fn is_even(&self) -> bool {
-        // Considering only the last digit.
-        match self.data.as_slice().head() {
-            Some(x) => x.is_even(),
-            None => true
-        }
-    }
-
-    /// Returns `true` if the number is not divisible by `2`.
-    #[inline]
-    fn is_odd(&self) -> bool { !self.is_even() }
-}
-
-impl ToPrimitive for BigUint {
-    #[inline]
-    fn to_i64(&self) -> Option<i64> {
-        self.to_u64().and_then(|n| {
-            // If top bit of u64 is set, it's too large to convert to i64.
-            if n >> 63 == 0 {
-                Some(n as i64)
-            } else {
-                None
-            }
-        })
-    }
-
-    // `DoubleBigDigit` size dependent
-    #[inline]
-    fn to_u64(&self) -> Option<u64> {
-        match self.data.len() {
-            0 => Some(0),
-            1 => Some(self.data.as_slice()[0] as u64),
-            2 => Some(BigDigit::to_doublebigdigit(self.data.as_slice()[1], self.data.as_slice()[0])
-                      as u64),
-            _ => None
-        }
-    }
-}
-
-impl FromPrimitive for BigUint {
-    #[inline]
-    fn from_i64(n: i64) -> Option<BigUint> {
-        if n > 0 {
-            FromPrimitive::from_u64(n as u64)
-        } else if n == 0 {
-            Some(Zero::zero())
-        } else {
-            None
-        }
-    }
-
-    // `DoubleBigDigit` size dependent
-    #[inline]
-    fn from_u64(n: u64) -> Option<BigUint> {
-        let n = match BigDigit::from_doublebigdigit(n) {
-            (0,  0)  => Zero::zero(),
-            (0,  n0) => BigUint::new(vec!(n0)),
-            (n1, n0) => BigUint::new(vec!(n0, n1))
-        };
-        Some(n)
-    }
-}
-
-/// A generic trait for converting a value to a `BigUint`.
-pub trait ToBigUint {
-    /// Converts the value of `self` to a `BigUint`.
-    fn to_biguint(&self) -> Option<BigUint>;
-}
-
-impl ToBigUint for BigInt {
-    #[inline]
-    fn to_biguint(&self) -> Option<BigUint> {
-        if self.sign == Plus {
-            Some(self.data.clone())
-        } else if self.sign == NoSign {
-            Some(Zero::zero())
-        } else {
-            None
-        }
-    }
-}
-
-impl ToBigUint for BigUint {
-    #[inline]
-    fn to_biguint(&self) -> Option<BigUint> {
-        Some(self.clone())
-    }
-}
-
-macro_rules! impl_to_biguint(
-    ($T:ty, $from_ty:path) => {
-        impl ToBigUint for $T {
-            #[inline]
-            fn to_biguint(&self) -> Option<BigUint> {
-                $from_ty(*self)
-            }
-        }
-    }
-)
-
-impl_to_biguint!(int,  FromPrimitive::from_int)
-impl_to_biguint!(i8,   FromPrimitive::from_i8)
-impl_to_biguint!(i16,  FromPrimitive::from_i16)
-impl_to_biguint!(i32,  FromPrimitive::from_i32)
-impl_to_biguint!(i64,  FromPrimitive::from_i64)
-impl_to_biguint!(uint, FromPrimitive::from_uint)
-impl_to_biguint!(u8,   FromPrimitive::from_u8)
-impl_to_biguint!(u16,  FromPrimitive::from_u16)
-impl_to_biguint!(u32,  FromPrimitive::from_u32)
-impl_to_biguint!(u64,  FromPrimitive::from_u64)
-
-impl ToStrRadix for BigUint {
-    fn to_str_radix(&self, radix: uint) -> String {
-        assert!(1 < radix && radix <= 16, "The radix must be within (1, 16]");
-        let (base, max_len) = get_radix_base(radix);
-        if base == BigDigit::base {
-            return fill_concat(self.data.as_slice(), radix, max_len)
-        }
-        return fill_concat(convert_base(self, base).as_slice(), radix, max_len);
-
-        fn convert_base(n: &BigUint, base: DoubleBigDigit) -> Vec<BigDigit> {
-            let divider    = base.to_biguint().unwrap();
-            let mut result = Vec::new();
-            let mut m      = n.clone();
-            while m >= divider {
-                let (d, m0) = m.div_mod_floor(&divider);
-                result.push(m0.to_uint().unwrap() as BigDigit);
-                m = d;
-            }
-            if !m.is_zero() {
-                result.push(m.to_uint().unwrap() as BigDigit);
-            }
-            return result;
-        }
-
-        fn fill_concat(v: &[BigDigit], radix: uint, l: uint) -> String {
-            if v.is_empty() {
-                return "0".to_string()
-            }
-            let mut s = String::with_capacity(v.len() * l);
-            for n in v.iter().rev() {
-                let ss = (*n as uint).to_str_radix(radix);
-                s.push_str("0".repeat(l - ss.len()).as_slice());
-                s.push_str(ss.as_slice());
-            }
-            s.as_slice().trim_left_chars('0').to_string()
-        }
-    }
-}
-
-impl FromStrRadix for BigUint {
-    /// Creates and initializes a `BigUint`.
-    #[inline]
-    fn from_str_radix(s: &str, radix: uint) -> Option<BigUint> {
-        BigUint::parse_bytes(s.as_bytes(), radix)
-    }
-}
-
-impl BigUint {
-    /// Creates and initializes a `BigUint`.
-    ///
-    /// The digits are be in base 2^32.
-    #[inline]
-    pub fn new(mut digits: Vec<BigDigit>) -> BigUint {
-        // omit trailing zeros
-        let new_len = digits.iter().rposition(|n| *n != 0).map_or(0, |p| p + 1);
-        digits.truncate(new_len);
-        BigUint { data: digits }
-    }
-
-    /// Creates and initializes a `BigUint`.
-    ///
-    /// The digits are be in base 2^32.
-    #[inline]
-    pub fn from_slice(slice: &[BigDigit]) -> BigUint {
-        BigUint::new(Vec::from_slice(slice))
-    }
-
-    /// Creates and initializes a `BigUint`.
-    pub fn parse_bytes(buf: &[u8], radix: uint) -> Option<BigUint> {
-        let (base, unit_len) = get_radix_base(radix);
-        let base_num = match base.to_biguint() {
-            Some(base_num) => base_num,
-            None => { return None; }
-        };
-
-        let mut end             = buf.len();
-        let mut n: BigUint      = Zero::zero();
-        let mut power: BigUint  = One::one();
-        loop {
-            let start = cmp::max(end, unit_len) - unit_len;
-            match uint::parse_bytes(buf[start..end], radix) {
-                Some(d) => {
-                    let d: Option<BigUint> = FromPrimitive::from_uint(d);
-                    match d {
-                        Some(d) => {
-                            // FIXME(#5992): assignment operator overloads
-                            // n += d * power;
-                            n = n + d * power;
-                        }
-                        None => { return None; }
-                    }
-                }
-                None => { return None; }
-            }
-            if end <= unit_len {
-                return Some(n);
-            }
-            end -= unit_len;
-            // FIXME(#5992): assignment operator overloads
-            // power *= base_num;
-            power = power * base_num;
-        }
-    }
-
-    #[inline]
-    fn shl_unit(&self, n_unit: uint) -> BigUint {
-        if n_unit == 0 || self.is_zero() { return (*self).clone(); }
-
-        BigUint::new(Vec::from_elem(n_unit, ZERO_BIG_DIGIT).append(self.data.as_slice()))
-    }
-
-    #[inline]
-    fn shl_bits(&self, n_bits: uint) -> BigUint {
-        if n_bits == 0 || self.is_zero() { return (*self).clone(); }
-
-        let mut carry = 0;
-        let mut shifted: Vec<BigDigit> = self.data.iter().map(|elem| {
-            let (hi, lo) = BigDigit::from_doublebigdigit(
-                (*elem as DoubleBigDigit) << n_bits | (carry as DoubleBigDigit)
-            );
-            carry = hi;
-            lo
-        }).collect();
-        if carry != 0 { shifted.push(carry); }
-        return BigUint::new(shifted);
-    }
-
-    #[inline]
-    fn shr_unit(&self, n_unit: uint) -> BigUint {
-        if n_unit == 0 { return (*self).clone(); }
-        if self.data.len() < n_unit { return Zero::zero(); }
-        return BigUint::from_slice(
-            self.data.slice(n_unit, self.data.len())
-        );
-    }
-
-    #[inline]
-    fn shr_bits(&self, n_bits: uint) -> BigUint {
-        if n_bits == 0 || self.data.is_empty() { return (*self).clone(); }
-
-        let mut borrow = 0;
-        let mut shifted_rev = Vec::with_capacity(self.data.len());
-        for elem in self.data.iter().rev() {
-            shifted_rev.push((*elem >> n_bits) | borrow);
-            borrow = *elem << (BigDigit::bits - n_bits);
-        }
-        let shifted = { shifted_rev.reverse(); shifted_rev };
-        return BigUint::new(shifted);
-    }
-
-    /// Determines the fewest bits necessary to express the `BigUint`.
-    pub fn bits(&self) -> uint {
-        if self.is_zero() { return 0; }
-        let zeros = self.data.last().unwrap().leading_zeros();
-        return self.data.len()*BigDigit::bits - zeros;
-    }
-}
-
-// `DoubleBigDigit` size dependent
-#[inline]
-fn get_radix_base(radix: uint) -> (DoubleBigDigit, uint) {
-    match radix {
-        2  => (4294967296, 32),
-        3  => (3486784401, 20),
-        4  => (4294967296, 16),
-        5  => (1220703125, 13),
-        6  => (2176782336, 12),
-        7  => (1977326743, 11),
-        8  => (1073741824, 10),
-        9  => (3486784401, 10),
-        10 => (1000000000, 9),
-        11 => (2357947691, 9),
-        12 => (429981696,  8),
-        13 => (815730721,  8),
-        14 => (1475789056, 8),
-        15 => (2562890625, 8),
-        16 => (4294967296, 8),
-        _  => fail!("The radix must be within (1, 16]")
-    }
-}
-
-/// A Sign is a `BigInt`'s composing element.
-#[deriving(PartialEq, PartialOrd, Eq, Ord, Clone, Show)]
-pub enum Sign { Minus, NoSign, Plus }
-
-impl Neg<Sign> for Sign {
-    /// Negate Sign value.
-    #[inline]
-    fn neg(&self) -> Sign {
-        match *self {
-          Minus => Plus,
-          NoSign  => NoSign,
-          Plus  => Minus
-        }
-    }
-}
-
-/// A big signed integer type.
-#[deriving(Clone)]
-pub struct BigInt {
-    sign: Sign,
-    data: BigUint
-}
-
-impl PartialEq for BigInt {
-    #[inline]
-    fn eq(&self, other: &BigInt) -> bool {
-        self.cmp(other) == Equal
-    }
-}
-
-impl Eq for BigInt {}
-
-impl PartialOrd for BigInt {
-    #[inline]
-    fn partial_cmp(&self, other: &BigInt) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for BigInt {
-    #[inline]
-    fn cmp(&self, other: &BigInt) -> Ordering {
-        let scmp = self.sign.cmp(&other.sign);
-        if scmp != Equal { return scmp; }
-
-        match self.sign {
-            NoSign  => Equal,
-            Plus  => self.data.cmp(&other.data),
-            Minus => other.data.cmp(&self.data),
-        }
-    }
-}
-
-impl Default for BigInt {
-    #[inline]
-    fn default() -> BigInt { Zero::zero() }
-}
-
-impl fmt::Show for BigInt {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.to_str_radix(10))
-    }
-}
-
-impl<S: hash::Writer> hash::Hash<S> for BigInt {
-    fn hash(&self, state: &mut S) {
-        (self.sign == Plus).hash(state);
-        self.data.hash(state);
-    }
-}
-
-impl FromStr for BigInt {
-    #[inline]
-    fn from_str(s: &str) -> Option<BigInt> {
-        FromStrRadix::from_str_radix(s, 10)
-    }
-}
-
-impl Num for BigInt {}
-
-impl Shl<uint, BigInt> for BigInt {
-    #[inline]
-    fn shl(&self, rhs: &uint) -> BigInt {
-        BigInt::from_biguint(self.sign, self.data << *rhs)
-    }
-}
-
-impl Shr<uint, BigInt> for BigInt {
-    #[inline]
-    fn shr(&self, rhs: &uint) -> BigInt {
-        BigInt::from_biguint(self.sign, self.data >> *rhs)
-    }
-}
-
-impl Zero for BigInt {
-    #[inline]
-    fn zero() -> BigInt {
-        BigInt::from_biguint(NoSign, Zero::zero())
-    }
-
-    #[inline]
-    fn is_zero(&self) -> bool { self.sign == NoSign }
-}
-
-impl One for BigInt {
-    #[inline]
-    fn one() -> BigInt {
-        BigInt::from_biguint(Plus, One::one())
-    }
-}
-
-impl Signed for BigInt {
-    #[inline]
-    fn abs(&self) -> BigInt {
-        match self.sign {
-            Plus | NoSign => self.clone(),
-            Minus => BigInt::from_biguint(Plus, self.data.clone())
-        }
-    }
-
-    #[inline]
-    fn abs_sub(&self, other: &BigInt) -> BigInt {
-        if *self <= *other { Zero::zero() } else { *self - *other }
-    }
-
-    #[inline]
-    fn signum(&self) -> BigInt {
-        match self.sign {
-            Plus  => BigInt::from_biguint(Plus, One::one()),
-            Minus => BigInt::from_biguint(Minus, One::one()),
-            NoSign  => Zero::zero(),
-        }
-    }
-
-    #[inline]
-    fn is_positive(&self) -> bool { self.sign == Plus }
-
-    #[inline]
-    fn is_negative(&self) -> bool { self.sign == Minus }
-}
-
-impl Add<BigInt, BigInt> for BigInt {
-    #[inline]
-    fn add(&self, other: &BigInt) -> BigInt {
-        match (self.sign, other.sign) {
-            (NoSign, _)      => other.clone(),
-            (_,    NoSign)   => self.clone(),
-            (Plus, Plus)   => BigInt::from_biguint(Plus, self.data + other.data),
-            (Plus, Minus)  => self - (-*other),
-            (Minus, Plus)  => other - (-*self),
-            (Minus, Minus) => -((-self) + (-*other))
-        }
-    }
-}
-
-impl Sub<BigInt, BigInt> for BigInt {
-    #[inline]
-    fn sub(&self, other: &BigInt) -> BigInt {
-        match (self.sign, other.sign) {
-            (NoSign, _)    => -other,
-            (_,    NoSign) => self.clone(),
-            (Plus, Plus) => match self.data.cmp(&other.data) {
-                Less    => BigInt::from_biguint(Minus, other.data - self.data),
-                Greater => BigInt::from_biguint(Plus, self.data - other.data),
-                Equal   => Zero::zero()
-            },
-            (Plus, Minus) => self + (-*other),
-            (Minus, Plus) => -((-self) + *other),
-            (Minus, Minus) => (-other) - (-*self)
-        }
-    }
-}
-
-impl Mul<BigInt, BigInt> for BigInt {
-    #[inline]
-    fn mul(&self, other: &BigInt) -> BigInt {
-        match (self.sign, other.sign) {
-            (NoSign, _)     | (_,     NoSign)  => Zero::zero(),
-            (Plus, Plus)  | (Minus, Minus) => {
-                BigInt::from_biguint(Plus, self.data * other.data)
-            },
-            (Plus, Minus) | (Minus, Plus) => {
-                BigInt::from_biguint(Minus, self.data * other.data)
-            }
-        }
-    }
-}
-
-impl Div<BigInt, BigInt> for BigInt {
-    #[inline]
-    fn div(&self, other: &BigInt) -> BigInt {
-        let (q, _) = self.div_rem(other);
-        q
-    }
-}
-
-impl Rem<BigInt, BigInt> for BigInt {
-    #[inline]
-    fn rem(&self, other: &BigInt) -> BigInt {
-        let (_, r) = self.div_rem(other);
-        r
-    }
-}
-
-impl Neg<BigInt> for BigInt {
-    #[inline]
-    fn neg(&self) -> BigInt {
-        BigInt::from_biguint(self.sign.neg(), self.data.clone())
-    }
-}
-
-impl CheckedAdd for BigInt {
-    #[inline]
-    fn checked_add(&self, v: &BigInt) -> Option<BigInt> {
-        return Some(self.add(v));
-    }
-}
-
-impl CheckedSub for BigInt {
-    #[inline]
-    fn checked_sub(&self, v: &BigInt) -> Option<BigInt> {
-        return Some(self.sub(v));
-    }
-}
-
-impl CheckedMul for BigInt {
-    #[inline]
-    fn checked_mul(&self, v: &BigInt) -> Option<BigInt> {
-        return Some(self.mul(v));
-    }
-}
-
-impl CheckedDiv for BigInt {
-    #[inline]
-    fn checked_div(&self, v: &BigInt) -> Option<BigInt> {
-        if v.is_zero() {
-            return None;
-        }
-        return Some(self.div(v));
-    }
-}
-
-
-impl Integer for BigInt {
-    #[inline]
-    fn div_rem(&self, other: &BigInt) -> (BigInt, BigInt) {
-        // r.sign == self.sign
-        let (d_ui, r_ui) = self.data.div_mod_floor(&other.data);
-        let d = BigInt::from_biguint(Plus, d_ui);
-        let r = BigInt::from_biguint(Plus, r_ui);
-        match (self.sign, other.sign) {
-            (_,    NoSign)   => fail!(),
-            (Plus, Plus)  | (NoSign, Plus)  => ( d,  r),
-            (Plus, Minus) | (NoSign, Minus) => (-d,  r),
-            (Minus, Plus)                 => (-d, -r),
-            (Minus, Minus)                => ( d, -r)
-        }
-    }
-
-    #[inline]
-    fn div_floor(&self, other: &BigInt) -> BigInt {
-        let (d, _) = self.div_mod_floor(other);
-        d
-    }
-
-    #[inline]
-    fn mod_floor(&self, other: &BigInt) -> BigInt {
-        let (_, m) = self.div_mod_floor(other);
-        m
-    }
-
-    fn div_mod_floor(&self, other: &BigInt) -> (BigInt, BigInt) {
-        // m.sign == other.sign
-        let (d_ui, m_ui) = self.data.div_rem(&other.data);
-        let d = BigInt::from_biguint(Plus, d_ui);
-        let m = BigInt::from_biguint(Plus, m_ui);
-        match (self.sign, other.sign) {
-            (_,    NoSign)   => fail!(),
-            (Plus, Plus)  | (NoSign, Plus)  => (d, m),
-            (Plus, Minus) | (NoSign, Minus) => if m.is_zero() {
-                (-d, Zero::zero())
-            } else {
-                (-d - One::one(), m + *other)
-            },
-            (Minus, Plus) => if m.is_zero() {
-                (-d, Zero::zero())
-            } else {
-                (-d - One::one(), other - m)
-            },
-            (Minus, Minus) => (d, -m)
-        }
-    }
-
-    /// Calculates the Greatest Common Divisor (GCD) of the number and `other`.
-    ///
-    /// The result is always positive.
-    #[inline]
-    fn gcd(&self, other: &BigInt) -> BigInt {
-        BigInt::from_biguint(Plus, self.data.gcd(&other.data))
-    }
-
-    /// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
-    #[inline]
-    fn lcm(&self, other: &BigInt) -> BigInt {
-        BigInt::from_biguint(Plus, self.data.lcm(&other.data))
-    }
-
-    /// Deprecated, use `is_multiple_of` instead.
-    #[deprecated = "function renamed to `is_multiple_of`"]
-    #[inline]
-    fn divides(&self, other: &BigInt) -> bool { return self.is_multiple_of(other); }
-
-    /// Returns `true` if the number is a multiple of `other`.
-    #[inline]
-    fn is_multiple_of(&self, other: &BigInt) -> bool { self.data.is_multiple_of(&other.data) }
-
-    /// Returns `true` if the number is divisible by `2`.
-    #[inline]
-    fn is_even(&self) -> bool { self.data.is_even() }
-
-    /// Returns `true` if the number is not divisible by `2`.
-    #[inline]
-    fn is_odd(&self) -> bool { self.data.is_odd() }
-}
-
-impl ToPrimitive for BigInt {
-    #[inline]
-    fn to_i64(&self) -> Option<i64> {
-        match self.sign {
-            Plus  => self.data.to_i64(),
-            NoSign  => Some(0),
-            Minus => {
-                self.data.to_u64().and_then(|n| {
-                    let m: u64 = 1 << 63;
-                    if n < m {
-                        Some(-(n as i64))
-                    } else if n == m {
-                        Some(i64::MIN)
-                    } else {
-                        None
-                    }
-                })
-            }
-        }
-    }
-
-    #[inline]
-    fn to_u64(&self) -> Option<u64> {
-        match self.sign {
-            Plus => self.data.to_u64(),
-            NoSign => Some(0),
-            Minus => None
-        }
-    }
-}
-
-impl FromPrimitive for BigInt {
-    #[inline]
-    fn from_i64(n: i64) -> Option<BigInt> {
-        if n > 0 {
-            FromPrimitive::from_u64(n as u64).and_then(|n| {
-                Some(BigInt::from_biguint(Plus, n))
-            })
-        } else if n < 0 {
-            FromPrimitive::from_u64(u64::MAX - (n as u64) + 1).and_then(
-                |n| {
-                    Some(BigInt::from_biguint(Minus, n))
-                })
-        } else {
-            Some(Zero::zero())
-        }
-    }
-
-    #[inline]
-    fn from_u64(n: u64) -> Option<BigInt> {
-        if n == 0 {
-            Some(Zero::zero())
-        } else {
-            FromPrimitive::from_u64(n).and_then(|n| {
-                Some(BigInt::from_biguint(Plus, n))
-            })
-        }
-    }
-}
-
-/// A generic trait for converting a value to a `BigInt`.
-pub trait ToBigInt {
-    /// Converts the value of `self` to a `BigInt`.
-    fn to_bigint(&self) -> Option<BigInt>;
-}
-
-impl ToBigInt for BigInt {
-    #[inline]
-    fn to_bigint(&self) -> Option<BigInt> {
-        Some(self.clone())
-    }
-}
-
-impl ToBigInt for BigUint {
-    #[inline]
-    fn to_bigint(&self) -> Option<BigInt> {
-        if self.is_zero() {
-            Some(Zero::zero())
-        } else {
-            Some(BigInt { sign: Plus, data: self.clone() })
-        }
-    }
-}
-
-macro_rules! impl_to_bigint(
-    ($T:ty, $from_ty:path) => {
-        impl ToBigInt for $T {
-            #[inline]
-            fn to_bigint(&self) -> Option<BigInt> {
-                $from_ty(*self)
-            }
-        }
-    }
-)
-
-impl_to_bigint!(int,  FromPrimitive::from_int)
-impl_to_bigint!(i8,   FromPrimitive::from_i8)
-impl_to_bigint!(i16,  FromPrimitive::from_i16)
-impl_to_bigint!(i32,  FromPrimitive::from_i32)
-impl_to_bigint!(i64,  FromPrimitive::from_i64)
-impl_to_bigint!(uint, FromPrimitive::from_uint)
-impl_to_bigint!(u8,   FromPrimitive::from_u8)
-impl_to_bigint!(u16,  FromPrimitive::from_u16)
-impl_to_bigint!(u32,  FromPrimitive::from_u32)
-impl_to_bigint!(u64,  FromPrimitive::from_u64)
-
-impl ToStrRadix for BigInt {
-    #[inline]
-    fn to_str_radix(&self, radix: uint) -> String {
-        match self.sign {
-            Plus  => self.data.to_str_radix(radix),
-            NoSign  => "0".to_string(),
-            Minus => format!("-{}", self.data.to_str_radix(radix)),
-        }
-    }
-}
-
-impl FromStrRadix for BigInt {
-    /// Creates and initializes a BigInt.
-    #[inline]
-    fn from_str_radix(s: &str, radix: uint) -> Option<BigInt> {
-        BigInt::parse_bytes(s.as_bytes(), radix)
-    }
-}
-
-pub trait RandBigInt {
-    /// Generate a random `BigUint` of the given bit size.
-    fn gen_biguint(&mut self, bit_size: uint) -> BigUint;
-
-    /// Generate a random BigInt of the given bit size.
-    fn gen_bigint(&mut self, bit_size: uint) -> BigInt;
-
-    /// Generate a random `BigUint` less than the given bound. Fails
-    /// when the bound is zero.
-    fn gen_biguint_below(&mut self, bound: &BigUint) -> BigUint;
-
-    /// Generate a random `BigUint` within the given range. The lower
-    /// bound is inclusive; the upper bound is exclusive. Fails when
-    /// the upper bound is not greater than the lower bound.
-    fn gen_biguint_range(&mut self, lbound: &BigUint, ubound: &BigUint) -> BigUint;
-
-    /// Generate a random `BigInt` within the given range. The lower
-    /// bound is inclusive; the upper bound is exclusive. Fails when
-    /// the upper bound is not greater than the lower bound.
-    fn gen_bigint_range(&mut self, lbound: &BigInt, ubound: &BigInt) -> BigInt;
-}
-
-impl<R: Rng> RandBigInt for R {
-    fn gen_biguint(&mut self, bit_size: uint) -> BigUint {
-        let (digits, rem) = bit_size.div_rem(&BigDigit::bits);
-        let mut data = Vec::with_capacity(digits+1);
-        for _ in range(0, digits) {
-            data.push(self.gen());
-        }
-        if rem > 0 {
-            let final_digit: BigDigit = self.gen();
-            data.push(final_digit >> (BigDigit::bits - rem));
-        }
-        BigUint::new(data)
-    }
-
-    fn gen_bigint(&mut self, bit_size: uint) -> BigInt {
-        // Generate a random BigUint...
-        let biguint = self.gen_biguint(bit_size);
-        // ...and then randomly assign it a Sign...
-        let sign = if biguint.is_zero() {
-            // ...except that if the BigUint is zero, we need to try
-            // again with probability 0.5. This is because otherwise,
-            // the probability of generating a zero BigInt would be
-            // double that of any other number.
-            if self.gen() {
-                return self.gen_bigint(bit_size);
-            } else {
-                NoSign
-            }
-        } else if self.gen() {
-            Plus
-        } else {
-            Minus
-        };
-        BigInt::from_biguint(sign, biguint)
-    }
-
-    fn gen_biguint_below(&mut self, bound: &BigUint) -> BigUint {
-        assert!(!bound.is_zero());
-        let bits = bound.bits();
-        loop {
-            let n = self.gen_biguint(bits);
-            if n < *bound { return n; }
-        }
-    }
-
-    fn gen_biguint_range(&mut self,
-                         lbound: &BigUint,
-                         ubound: &BigUint)
-                         -> BigUint {
-        assert!(*lbound < *ubound);
-        return *lbound + self.gen_biguint_below(&(*ubound - *lbound));
-    }
-
-    fn gen_bigint_range(&mut self,
-                        lbound: &BigInt,
-                        ubound: &BigInt)
-                        -> BigInt {
-        assert!(*lbound < *ubound);
-        let delta = (*ubound - *lbound).to_biguint().unwrap();
-        return *lbound + self.gen_biguint_below(&delta).to_bigint().unwrap();
-    }
-}
-
-impl BigInt {
-    /// Creates and initializes a BigInt.
-    ///
-    /// The digits are be in base 2^32.
-    #[inline]
-    pub fn new(sign: Sign, digits: Vec<BigDigit>) -> BigInt {
-        BigInt::from_biguint(sign, BigUint::new(digits))
-    }
-
-    /// Creates and initializes a `BigInt`.
-    ///
-    /// The digits are be in base 2^32.
-    #[inline]
-    pub fn from_biguint(sign: Sign, data: BigUint) -> BigInt {
-        if sign == NoSign || data.is_zero() {
-            return BigInt { sign: NoSign, data: Zero::zero() };
-        }
-        BigInt { sign: sign, data: data }
-    }
-
-    /// Creates and initializes a `BigInt`.
-    #[inline]
-    pub fn from_slice(sign: Sign, slice: &[BigDigit]) -> BigInt {
-        BigInt::from_biguint(sign, BigUint::from_slice(slice))
-    }
-
-    /// Creates and initializes a `BigInt`.
-    pub fn parse_bytes(buf: &[u8], radix: uint) -> Option<BigInt> {
-        if buf.is_empty() { return None; }
-        let mut sign  = Plus;
-        let mut start = 0;
-        if buf[0] == b'-' {
-            sign  = Minus;
-            start = 1;
-        }
-        return BigUint::parse_bytes(buf[start..], radix)
-            .map(|bu| BigInt::from_biguint(sign, bu));
-    }
-
-    /// Converts this `BigInt` into a `BigUint`, if it's not negative.
-    #[inline]
-    pub fn to_biguint(&self) -> Option<BigUint> {
-        match self.sign {
-            Plus => Some(self.data.clone()),
-            NoSign => Some(Zero::zero()),
-            Minus => None
-        }
-    }
-}
-
-#[cfg(test)]
-mod biguint_tests {
-    use Integer;
-    use super::{BigDigit, BigUint, ToBigUint};
-    use super::{Plus, BigInt, RandBigInt, ToBigInt};
-
-    use std::cmp::{Less, Equal, Greater};
-    use std::from_str::FromStr;
-    use std::i64;
-    use std::num::{Zero, One, FromStrRadix, ToStrRadix};
-    use std::num::{ToPrimitive, FromPrimitive};
-    use std::num::CheckedDiv;
-    use std::rand::task_rng;
-    use std::u64;
-    use std::hash::hash;
-
-    #[test]
-    fn test_from_slice() {
-        fn check(slice: &[BigDigit], data: &[BigDigit]) {
-            assert!(data == BigUint::from_slice(slice).data.as_slice());
-        }
-        check([1], [1]);
-        check([0, 0, 0], []);
-        check([1, 2, 0, 0], [1, 2]);
-        check([0, 0, 1, 2], [0, 0, 1, 2]);
-        check([0, 0, 1, 2, 0, 0], [0, 0, 1, 2]);
-        check([-1], [-1]);
-    }
-
-    #[test]
-    fn test_cmp() {
-        let data: [&[_], ..7] = [ &[], &[1], &[2], &[-1], &[0, 1], &[2, 1], &[1, 1, 1]  ];
-        let data: Vec<BigUint> = data.iter().map(|v| BigUint::from_slice(*v)).collect();
-        for (i, ni) in data.iter().enumerate() {
-            for (j0, nj) in data.slice(i, data.len()).iter().enumerate() {
-                let j = j0 + i;
-                if i == j {
-                    assert_eq!(ni.cmp(nj), Equal);
-                    assert_eq!(nj.cmp(ni), Equal);
-                    assert_eq!(ni, nj);
-                    assert!(!(ni != nj));
-                    assert!(ni <= nj);
-                    assert!(ni >= nj);
-                    assert!(!(ni < nj));
-                    assert!(!(ni > nj));
-                } else {
-                    assert_eq!(ni.cmp(nj), Less);
-                    assert_eq!(nj.cmp(ni), Greater);
-
-                    assert!(!(ni == nj));
-                    assert!(ni != nj);
-
-                    assert!(ni <= nj);
-                    assert!(!(ni >= nj));
-                    assert!(ni < nj);
-                    assert!(!(ni > nj));
-
-                    assert!(!(nj <= ni));
-                    assert!(nj >= ni);
-                    assert!(!(nj < ni));
-                    assert!(nj > ni);
-                }
-            }
-        }
-    }
-
-    #[test]
-    fn test_hash() {
-        let a = BigUint::new(vec!());
-        let b = BigUint::new(vec!(0));
-        let c = BigUint::new(vec!(1));
-        let d = BigUint::new(vec!(1,0,0,0,0,0));
-        let e = BigUint::new(vec!(0,0,0,0,0,1));
-        assert!(hash(&a) == hash(&b));
-        assert!(hash(&b) != hash(&c));
-        assert!(hash(&c) == hash(&d));
-        assert!(hash(&d) != hash(&e));
-    }
-
-    #[test]
-    fn test_bitand() {
-        fn check(left: &[BigDigit],
-                 right: &[BigDigit],
-                 expected: &[BigDigit]) {
-            assert_eq!(BigUint::from_slice(left) & BigUint::from_slice(right),
-                       BigUint::from_slice(expected));
-        }
-        check([], [], []);
-        check([268, 482, 17],
-              [964, 54],
-              [260, 34]);
-    }
-
-    #[test]
-    fn test_bitor() {
-        fn check(left: &[BigDigit],
-                 right: &[BigDigit],
-                 expected: &[BigDigit]) {
-            assert_eq!(BigUint::from_slice(left) | BigUint::from_slice(right),
-                       BigUint::from_slice(expected));
-        }
-        check([], [], []);
-        check([268, 482, 17],
-              [964, 54],
-              [972, 502, 17]);
-    }
-
-    #[test]
-    fn test_bitxor() {
-        fn check(left: &[BigDigit],
-                 right: &[BigDigit],
-                 expected: &[BigDigit]) {
-            assert_eq!(BigUint::from_slice(left) ^ BigUint::from_slice(right),
-                       BigUint::from_slice(expected));
-        }
-        check([], [], []);
-        check([268, 482, 17],
-              [964, 54],
-              [712, 468, 17]);
-    }
-
-    #[test]
-    fn test_shl() {
-        fn check(s: &str, shift: uint, ans: &str) {
-            let opt_biguint: Option<BigUint> = FromStrRadix::from_str_radix(s, 16);
-            let bu = (opt_biguint.unwrap() << shift).to_str_radix(16);
-            assert_eq!(bu.as_slice(), ans);
-        }
-
-        check("0", 3, "0");
-        check("1", 3, "8");
-
-        check("1\
-               0000\
-               0000\
-               0000\
-               0001\
-               0000\
-               0000\
-               0000\
-               0001",
-              3,
-              "8\
-               0000\
-               0000\
-               0000\
-               0008\
-               0000\
-               0000\
-               0000\
-               0008");
-        check("1\
-               0000\
-               0001\
-               0000\
-               0001",
-              2,
-              "4\
-               0000\
-               0004\
-               0000\
-               0004");
-        check("1\
-               0001\
-               0001",
-              1,
-              "2\
-               0002\
-               0002");
-
-        check("\
-              4000\
-              0000\
-              0000\
-              0000",
-              3,
-              "2\
-              0000\
-              0000\
-              0000\
-              0000");
-        check("4000\
-              0000",
-              2,
-              "1\
-              0000\
-              0000");
-        check("4000",
-              2,
-              "1\
-              0000");
-
-        check("4000\
-              0000\
-              0000\
-              0000",
-              67,
-              "2\
-              0000\
-              0000\
-              0000\
-              0000\
-              0000\
-              0000\
-              0000\
-              0000");
-        check("4000\
-              0000",
-              35,
-              "2\
-              0000\
-              0000\
-              0000\
-              0000");
-        check("4000",
-              19,
-              "2\
-              0000\
-              0000");
-
-        check("fedc\
-              ba98\
-              7654\
-              3210\
-              fedc\
-              ba98\
-              7654\
-              3210",
-              4,
-              "f\
-              edcb\
-              a987\
-              6543\
-              210f\
-              edcb\
-              a987\
-              6543\
-              2100");
-        check("88887777666655554444333322221111", 16,
-              "888877776666555544443333222211110000");
-    }
-
-    #[test]
-    fn test_shr() {
-        fn check(s: &str, shift: uint, ans: &str) {
-            let opt_biguint: Option<BigUint> =
-                FromStrRadix::from_str_radix(s, 16);
-            let bu = (opt_biguint.unwrap() >> shift).to_str_radix(16);
-            assert_eq!(bu.as_slice(), ans);
-        }
-
-        check("0", 3, "0");
-        check("f", 3, "1");
-
-        check("1\
-              0000\
-              0000\
-              0000\
-              0001\
-              0000\
-              0000\
-              0000\
-              0001",
-              3,
-              "2000\
-              0000\
-              0000\
-              0000\
-              2000\
-              0000\
-              0000\
-              0000");
-        check("1\
-              0000\
-              0001\
-              0000\
-              0001",
-              2,
-              "4000\
-              0000\
-              4000\
-              0000");
-        check("1\
-              0001\
-              0001",
-              1,
-              "8000\
-              8000");
-
-        check("2\
-              0000\
-              0000\
-              0000\
-              0001\
-              0000\
-              0000\
-              0000\
-              0001",
-              67,
-              "4000\
-              0000\
-              0000\
-              0000");
-        check("2\
-              0000\
-              0001\
-              0000\
-              0001",
-              35,
-              "4000\
-              0000");
-        check("2\
-              0001\
-              0001",
-              19,
-              "4000");
-
-        check("1\
-              0000\
-              0000\
-              0000\
-              0000",
-              1,
-              "8000\
-              0000\
-              0000\
-              0000");
-        check("1\
-              0000\
-              0000",
-              1,
-              "8000\
-              0000");
-        check("1\
-              0000",
-              1,
-              "8000");
-        check("f\
-              edcb\
-              a987\
-              6543\
-              210f\
-              edcb\
-              a987\
-              6543\
-              2100",
-              4,
-              "fedc\
-              ba98\
-              7654\
-              3210\
-              fedc\
-              ba98\
-              7654\
-              3210");
-
-        check("888877776666555544443333222211110000", 16,
-              "88887777666655554444333322221111");
-    }
-
-    // `DoubleBigDigit` size dependent
-    #[test]
-    fn test_convert_i64() {
-        fn check(b1: BigUint, i: i64) {
-            let b2: BigUint = FromPrimitive::from_i64(i).unwrap();
-            assert!(b1 == b2);
-            assert!(b1.to_i64().unwrap() == i);
-        }
-
-        check(Zero::zero(), 0);
-        check(One::one(), 1);
-        check(i64::MAX.to_biguint().unwrap(), i64::MAX);
-
-        check(BigUint::new(vec!(           )), 0);
-        check(BigUint::new(vec!( 1         )), (1 << (0*BigDigit::bits)));
-        check(BigUint::new(vec!(-1         )), (1 << (1*BigDigit::bits)) - 1);
-        check(BigUint::new(vec!( 0,  1     )), (1 << (1*BigDigit::bits)));
-        check(BigUint::new(vec!(-1, -1 >> 1)), i64::MAX);
-
-        assert_eq!(i64::MIN.to_biguint(), None);
-        assert_eq!(BigUint::new(vec!(-1, -1    )).to_i64(), None);
-        assert_eq!(BigUint::new(vec!( 0,  0,  1)).to_i64(), None);
-        assert_eq!(BigUint::new(vec!(-1, -1, -1)).to_i64(), None);
-    }
-
-    // `DoubleBigDigit` size dependent
-    #[test]
-    fn test_convert_u64() {
-        fn check(b1: BigUint, u: u64) {
-            let b2: BigUint = FromPrimitive::from_u64(u).unwrap();
-            assert!(b1 == b2);
-            assert!(b1.to_u64().unwrap() == u);
-        }
-
-        check(Zero::zero(), 0);
-        check(One::one(), 1);
-        check(u64::MIN.to_biguint().unwrap(), u64::MIN);
-        check(u64::MAX.to_biguint().unwrap(), u64::MAX);
-
-        check(BigUint::new(vec!(      )), 0);
-        check(BigUint::new(vec!( 1    )), (1 << (0*BigDigit::bits)));
-        check(BigUint::new(vec!(-1    )), (1 << (1*BigDigit::bits)) - 1);
-        check(BigUint::new(vec!( 0,  1)), (1 << (1*BigDigit::bits)));
-        check(BigUint::new(vec!(-1, -1)), u64::MAX);
-
-        assert_eq!(BigUint::new(vec!( 0,  0,  1)).to_u64(), None);
-        assert_eq!(BigUint::new(vec!(-1, -1, -1)).to_u64(), None);
-    }
-
-    #[test]
-    fn test_convert_to_bigint() {
-        fn check(n: BigUint, ans: BigInt) {
-            assert_eq!(n.to_bigint().unwrap(), ans);
-            assert_eq!(n.to_bigint().unwrap().to_biguint().unwrap(), n);
-        }
-        check(Zero::zero(), Zero::zero());
-        check(BigUint::new(vec!(1,2,3)),
-              BigInt::from_biguint(Plus, BigUint::new(vec!(1,2,3))));
-    }
-
-    static SUM_TRIPLES: &'static [(&'static [BigDigit],
-                                   &'static [BigDigit],
-                                   &'static [BigDigit])] = &[
-        (&[],          &[],       &[]),
-        (&[],          &[ 1],     &[ 1]),
-        (&[ 1],        &[ 1],     &[ 2]),
-        (&[ 1],        &[ 1,  1], &[ 2,  1]),
-        (&[ 1],        &[-1],     &[ 0,  1]),
-        (&[ 1],        &[-1, -1], &[ 0,  0, 1]),
-        (&[-1, -1],    &[-1, -1], &[-2, -1, 1]),
-        (&[ 1,  1, 1], &[-1, -1], &[ 0,  1, 2]),
-        (&[ 2,  2, 1], &[-1, -2], &[ 1,  1, 2])
-    ];
-
-    #[test]
-    fn test_add() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(a + b == c);
-            assert!(b + a == c);
-        }
-    }
-
-    #[test]
-    fn test_sub() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(c - a == b);
-            assert!(c - b == a);
-        }
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_sub_fail_on_underflow() {
-        let (a, b) : (BigUint, BigUint) = (Zero::zero(), One::one());
-        a - b;
-    }
-
-    static MUL_TRIPLES: &'static [(&'static [BigDigit],
-                                   &'static [BigDigit],
-                                   &'static [BigDigit])] = &[
-        (&[],               &[],               &[]),
-        (&[],               &[ 1],             &[]),
-        (&[ 2],             &[],               &[]),
-        (&[ 1],             &[ 1],             &[1]),
-        (&[ 2],             &[ 3],             &[ 6]),
-        (&[ 1],             &[ 1,  1,  1],     &[1, 1,  1]),
-        (&[ 1,  2,  3],     &[ 3],             &[ 3,  6,  9]),
-        (&[ 1,  1,  1],     &[-1],             &[-1, -1, -1]),
-        (&[ 1,  2,  3],     &[-1],             &[-1, -2, -2, 2]),
-        (&[ 1,  2,  3,  4], &[-1],             &[-1, -2, -2, -2, 3]),
-        (&[-1],             &[-1],             &[ 1, -2]),
-        (&[-1, -1],         &[-1],             &[ 1, -1, -2]),
-        (&[-1, -1, -1],     &[-1],             &[ 1, -1, -1, -2]),
-        (&[-1, -1, -1, -1], &[-1],             &[ 1, -1, -1, -1, -2]),
-        (&[-1/2 + 1],       &[ 2],             &[ 0,  1]),
-        (&[0, -1/2 + 1],    &[ 2],             &[ 0,  0,  1]),
-        (&[ 1,  2],         &[ 1,  2,  3],     &[1, 4,  7,  6]),
-        (&[-1, -1],         &[-1, -1, -1],     &[1, 0, -1, -2, -1]),
-        (&[-1, -1, -1],     &[-1, -1, -1, -1], &[1, 0,  0, -1, -2, -1, -1]),
-        (&[ 0,  0,  1],     &[ 1,  2,  3],     &[0, 0,  1,  2,  3]),
-        (&[ 0,  0,  1],     &[ 0,  0,  0,  1], &[0, 0,  0,  0,  0,  1])
-    ];
-
-    static DIV_REM_QUADRUPLES: &'static [(&'static [BigDigit],
-                                           &'static [BigDigit],
-                                           &'static [BigDigit],
-                                           &'static [BigDigit])]
-        = &[
-            (&[ 1],        &[ 2], &[],               &[1]),
-            (&[ 1,  1],    &[ 2], &[-1/2+1],         &[1]),
-            (&[ 1,  1, 1], &[ 2], &[-1/2+1, -1/2+1], &[1]),
-            (&[ 0,  1],    &[-1], &[1],              &[1]),
-            (&[-1, -1],    &[-2], &[2, 1],           &[3])
-        ];
-
-    #[test]
-    fn test_mul() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(a * b == c);
-            assert!(b * a == c);
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-            let d = BigUint::from_slice(d_vec);
-
-            assert!(a == b * c + d);
-            assert!(a == c * b + d);
-        }
-    }
-
-    #[test]
-    fn test_div_rem() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            if !a.is_zero() {
-                assert_eq!(c.div_rem(&a), (b.clone(), Zero::zero()));
-            }
-            if !b.is_zero() {
-                assert_eq!(c.div_rem(&b), (a.clone(), Zero::zero()));
-            }
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-            let d = BigUint::from_slice(d_vec);
-
-            if !b.is_zero() { assert!(a.div_rem(&b) == (c, d)); }
-        }
-    }
-
-    #[test]
-    fn test_checked_add() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(a.checked_add(&b).unwrap() == c);
-            assert!(b.checked_add(&a).unwrap() == c);
-        }
-    }
-
-    #[test]
-    fn test_checked_sub() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(c.checked_sub(&a).unwrap() == b);
-            assert!(c.checked_sub(&b).unwrap() == a);
-
-            if a > c {
-                assert!(a.checked_sub(&c).is_none());
-            }
-            if b > c {
-                assert!(b.checked_sub(&c).is_none());
-            }
-        }
-    }
-
-    #[test]
-    fn test_checked_mul() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            assert!(a.checked_mul(&b).unwrap() == c);
-            assert!(b.checked_mul(&a).unwrap() == c);
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-            let d = BigUint::from_slice(d_vec);
-
-            assert!(a == b.checked_mul(&c).unwrap() + d);
-            assert!(a == c.checked_mul(&b).unwrap() + d);
-        }
-    }
-
-    #[test]
-    fn test_checked_div() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigUint::from_slice(a_vec);
-            let b = BigUint::from_slice(b_vec);
-            let c = BigUint::from_slice(c_vec);
-
-            if !a.is_zero() {
-                assert!(c.checked_div(&a).unwrap() == b);
-            }
-            if !b.is_zero() {
-                assert!(c.checked_div(&b).unwrap() == a);
-            }
-
-            assert!(c.checked_div(&Zero::zero()).is_none());
-        }
-    }
-
-    #[test]
-    fn test_gcd() {
-        fn check(a: uint, b: uint, c: uint) {
-            let big_a: BigUint = FromPrimitive::from_uint(a).unwrap();
-            let big_b: BigUint = FromPrimitive::from_uint(b).unwrap();
-            let big_c: BigUint = FromPrimitive::from_uint(c).unwrap();
-
-            assert_eq!(big_a.gcd(&big_b), big_c);
-        }
-
-        check(10, 2, 2);
-        check(10, 3, 1);
-        check(0, 3, 3);
-        check(3, 3, 3);
-        check(56, 42, 14);
-    }
-
-    #[test]
-    fn test_lcm() {
-        fn check(a: uint, b: uint, c: uint) {
-            let big_a: BigUint = FromPrimitive::from_uint(a).unwrap();
-            let big_b: BigUint = FromPrimitive::from_uint(b).unwrap();
-            let big_c: BigUint = FromPrimitive::from_uint(c).unwrap();
-
-            assert_eq!(big_a.lcm(&big_b), big_c);
-        }
-
-        check(1, 0, 0);
-        check(0, 1, 0);
-        check(1, 1, 1);
-        check(8, 9, 72);
-        check(11, 5, 55);
-        check(99, 17, 1683);
-    }
-
-    #[test]
-    fn test_is_even() {
-        let one: BigUint = FromStr::from_str("1").unwrap();
-        let two: BigUint = FromStr::from_str("2").unwrap();
-        let thousand: BigUint = FromStr::from_str("1000").unwrap();
-        let big: BigUint = FromStr::from_str("1000000000000000000000").unwrap();
-        let bigger: BigUint = FromStr::from_str("1000000000000000000001").unwrap();
-        assert!(one.is_odd());
-        assert!(two.is_even());
-        assert!(thousand.is_even());
-        assert!(big.is_even());
-        assert!(bigger.is_odd());
-        assert!((one << 64).is_even());
-        assert!(((one << 64) + one).is_odd());
-    }
-
-    fn to_str_pairs() -> Vec<(BigUint, Vec<(uint, String)>)> {
-        let bits = BigDigit::bits;
-        vec!(( Zero::zero(), vec!(
-            (2, "0".to_string()), (3, "0".to_string())
-        )), ( BigUint::from_slice([ 0xff ]), vec!(
-            (2,  "11111111".to_string()),
-            (3,  "100110".to_string()),
-            (4,  "3333".to_string()),
-            (5,  "2010".to_string()),
-            (6,  "1103".to_string()),
-            (7,  "513".to_string()),
-            (8,  "377".to_string()),
-            (9,  "313".to_string()),
-            (10, "255".to_string()),
-            (11, "212".to_string()),
-            (12, "193".to_string()),
-            (13, "168".to_string()),
-            (14, "143".to_string()),
-            (15, "120".to_string()),
-            (16, "ff".to_string())
-        )), ( BigUint::from_slice([ 0xfff ]), vec!(
-            (2,  "111111111111".to_string()),
-            (4,  "333333".to_string()),
-            (16, "fff".to_string())
-        )), ( BigUint::from_slice([ 1, 2 ]), vec!(
-            (2,
-             format!("10{}1", "0".repeat(bits - 1))),
-            (4,
-             format!("2{}1", "0".repeat(bits / 2 - 1))),
-            (10, match bits {
-                32 => "8589934593".to_string(),
-                16 => "131073".to_string(),
-                _ => fail!()
-            }),
-            (16,
-             format!("2{}1", "0".repeat(bits / 4 - 1)))
-        )), ( BigUint::from_slice([ 1, 2, 3 ]), vec!(
-            (2,
-             format!("11{}10{}1",
-                     "0".repeat(bits - 2),
-                     "0".repeat(bits - 1))),
-            (4,
-             format!("3{}2{}1",
-                     "0".repeat(bits / 2 - 1),
-                     "0".repeat(bits / 2 - 1))),
-            (10, match bits {
-                32 => "55340232229718589441".to_string(),
-                16 => "12885032961".to_string(),
-                _ => fail!()
-            }),
-            (16,
-             format!("3{}2{}1",
-                     "0".repeat(bits / 4 - 1),
-                     "0".repeat(bits / 4 - 1)))
-        )) )
-    }
-
-    #[test]
-    fn test_to_str_radix() {
-        let r = to_str_pairs();
-        for num_pair in r.iter() {
-            let &(ref n, ref rs) = num_pair;
-            for str_pair in rs.iter() {
-                let &(ref radix, ref str) = str_pair;
-                assert_eq!(n.to_str_radix(*radix).as_slice(),
-                           str.as_slice());
-            }
-        }
-    }
-
-    #[test]
-    fn test_from_str_radix() {
-        let r = to_str_pairs();
-        for num_pair in r.iter() {
-            let &(ref n, ref rs) = num_pair;
-            for str_pair in rs.iter() {
-                let &(ref radix, ref str) = str_pair;
-                assert_eq!(n,
-                           &FromStrRadix::from_str_radix(str.as_slice(),
-                                                         *radix).unwrap());
-            }
-        }
-
-        let zed: Option<BigUint> = FromStrRadix::from_str_radix("Z", 10);
-        assert_eq!(zed, None);
-        let blank: Option<BigUint> = FromStrRadix::from_str_radix("_", 2);
-        assert_eq!(blank, None);
-        let minus_one: Option<BigUint> = FromStrRadix::from_str_radix("-1",
-                                                                      10);
-        assert_eq!(minus_one, None);
-    }
-
-    #[test]
-    fn test_factor() {
-        fn factor(n: uint) -> BigUint {
-            let mut f: BigUint = One::one();
-            for i in range(2, n + 1) {
-                // FIXME(#5992): assignment operator overloads
-                // f *= FromPrimitive::from_uint(i);
-                f = f * FromPrimitive::from_uint(i).unwrap();
-            }
-            return f;
-        }
-
-        fn check(n: uint, s: &str) {
-            let n = factor(n);
-            let ans = match FromStrRadix::from_str_radix(s, 10) {
-                Some(x) => x, None => fail!()
-            };
-            assert_eq!(n, ans);
-        }
-
-        check(3, "6");
-        check(10, "3628800");
-        check(20, "2432902008176640000");
-        check(30, "265252859812191058636308480000000");
-    }
-
-    #[test]
-    fn test_bits() {
-        assert_eq!(BigUint::new(vec!(0,0,0,0)).bits(), 0);
-        let n: BigUint = FromPrimitive::from_uint(0).unwrap();
-        assert_eq!(n.bits(), 0);
-        let n: BigUint = FromPrimitive::from_uint(1).unwrap();
-        assert_eq!(n.bits(), 1);
-        let n: BigUint = FromPrimitive::from_uint(3).unwrap();
-        assert_eq!(n.bits(), 2);
-        let n: BigUint = FromStrRadix::from_str_radix("4000000000", 16).unwrap();
-        assert_eq!(n.bits(), 39);
-        let one: BigUint = One::one();
-        assert_eq!((one << 426).bits(), 427);
-    }
-
-    #[test]
-    fn test_rand() {
-        let mut rng = task_rng();
-        let _n: BigUint = rng.gen_biguint(137);
-        assert!(rng.gen_biguint(0).is_zero());
-    }
-
-    #[test]
-    fn test_rand_range() {
-        let mut rng = task_rng();
-
-        for _ in range(0u, 10) {
-            assert_eq!(rng.gen_bigint_range(&FromPrimitive::from_uint(236).unwrap(),
-                                            &FromPrimitive::from_uint(237).unwrap()),
-                       FromPrimitive::from_uint(236).unwrap());
-        }
-
-        let l = FromPrimitive::from_uint(403469000 + 2352).unwrap();
-        let u = FromPrimitive::from_uint(403469000 + 3513).unwrap();
-        for _ in range(0u, 1000) {
-            let n: BigUint = rng.gen_biguint_below(&u);
-            assert!(n < u);
-
-            let n: BigUint = rng.gen_biguint_range(&l, &u);
-            assert!(n >= l);
-            assert!(n < u);
-        }
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_zero_rand_range() {
-        task_rng().gen_biguint_range(&FromPrimitive::from_uint(54).unwrap(),
-                                     &FromPrimitive::from_uint(54).unwrap());
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_negative_rand_range() {
-        let mut rng = task_rng();
-        let l = FromPrimitive::from_uint(2352).unwrap();
-        let u = FromPrimitive::from_uint(3513).unwrap();
-        // Switching u and l should fail:
-        let _n: BigUint = rng.gen_biguint_range(&u, &l);
-    }
-}
-
-#[cfg(test)]
-mod bigint_tests {
-    use Integer;
-    use super::{BigDigit, BigUint, ToBigUint};
-    use super::{Sign, Minus, NoSign, Plus, BigInt, RandBigInt, ToBigInt};
-
-    use std::cmp::{Less, Equal, Greater};
-    use std::i64;
-    use std::num::CheckedDiv;
-    use std::num::{Zero, One, FromStrRadix, ToStrRadix};
-    use std::num::{ToPrimitive, FromPrimitive};
-    use std::rand::task_rng;
-    use std::u64;
-    use std::hash::hash;
-
-    #[test]
-    fn test_from_biguint() {
-        fn check(inp_s: Sign, inp_n: uint, ans_s: Sign, ans_n: uint) {
-            let inp = BigInt::from_biguint(inp_s, FromPrimitive::from_uint(inp_n).unwrap());
-            let ans = BigInt { sign: ans_s, data: FromPrimitive::from_uint(ans_n).unwrap()};
-            assert_eq!(inp, ans);
-        }
-        check(Plus, 1, Plus, 1);
-        check(Plus, 0, NoSign, 0);
-        check(Minus, 1, Minus, 1);
-        check(NoSign, 1, NoSign, 0);
-    }
-
-    #[test]
-    fn test_cmp() {
-        let vs: [&[BigDigit], ..4] = [ &[2 as BigDigit], &[1, 1], &[2, 1], &[1, 1, 1] ];
-        let mut nums = Vec::new();
-        for s in vs.iter().rev() {
-            nums.push(BigInt::from_slice(Minus, *s));
-        }
-        nums.push(Zero::zero());
-        nums.extend(vs.iter().map(|s| BigInt::from_slice(Plus, *s)));
-
-        for (i, ni) in nums.iter().enumerate() {
-            for (j0, nj) in nums.slice(i, nums.len()).iter().enumerate() {
-                let j = i + j0;
-                if i == j {
-                    assert_eq!(ni.cmp(nj), Equal);
-                    assert_eq!(nj.cmp(ni), Equal);
-                    assert_eq!(ni, nj);
-                    assert!(!(ni != nj));
-                    assert!(ni <= nj);
-                    assert!(ni >= nj);
-                    assert!(!(ni < nj));
-                    assert!(!(ni > nj));
-                } else {
-                    assert_eq!(ni.cmp(nj), Less);
-                    assert_eq!(nj.cmp(ni), Greater);
-
-                    assert!(!(ni == nj));
-                    assert!(ni != nj);
-
-                    assert!(ni <= nj);
-                    assert!(!(ni >= nj));
-                    assert!(ni < nj);
-                    assert!(!(ni > nj));
-
-                    assert!(!(nj <= ni));
-                    assert!(nj >= ni);
-                    assert!(!(nj < ni));
-                    assert!(nj > ni);
-                }
-            }
-        }
-    }
-
-    #[test]
-    fn test_hash() {
-        let a = BigInt::new(NoSign, vec!());
-        let b = BigInt::new(NoSign, vec!(0));
-        let c = BigInt::new(Plus, vec!(1));
-        let d = BigInt::new(Plus, vec!(1,0,0,0,0,0));
-        let e = BigInt::new(Plus, vec!(0,0,0,0,0,1));
-        let f = BigInt::new(Minus, vec!(1));
-        assert!(hash(&a) == hash(&b));
-        assert!(hash(&b) != hash(&c));
-        assert!(hash(&c) == hash(&d));
-        assert!(hash(&d) != hash(&e));
-        assert!(hash(&c) != hash(&f));
-    }
-
-    #[test]
-    fn test_convert_i64() {
-        fn check(b1: BigInt, i: i64) {
-            let b2: BigInt = FromPrimitive::from_i64(i).unwrap();
-            assert!(b1 == b2);
-            assert!(b1.to_i64().unwrap() == i);
-        }
-
-        check(Zero::zero(), 0);
-        check(One::one(), 1);
-        check(i64::MIN.to_bigint().unwrap(), i64::MIN);
-        check(i64::MAX.to_bigint().unwrap(), i64::MAX);
-
-        assert_eq!(
-            (i64::MAX as u64 + 1).to_bigint().unwrap().to_i64(),
-            None);
-
-        assert_eq!(
-            BigInt::from_biguint(Plus,  BigUint::new(vec!(1, 2, 3, 4, 5))).to_i64(),
-            None);
-
-        assert_eq!(
-            BigInt::from_biguint(Minus, BigUint::new(vec!(1,0,0,1<<(BigDigit::bits-1)))).to_i64(),
-            None);
-
-        assert_eq!(
-            BigInt::from_biguint(Minus, BigUint::new(vec!(1, 2, 3, 4, 5))).to_i64(),
-            None);
-    }
-
-    #[test]
-    fn test_convert_u64() {
-        fn check(b1: BigInt, u: u64) {
-            let b2: BigInt = FromPrimitive::from_u64(u).unwrap();
-            assert!(b1 == b2);
-            assert!(b1.to_u64().unwrap() == u);
-        }
-
-        check(Zero::zero(), 0);
-        check(One::one(), 1);
-        check(u64::MIN.to_bigint().unwrap(), u64::MIN);
-        check(u64::MAX.to_bigint().unwrap(), u64::MAX);
-
-        assert_eq!(
-            BigInt::from_biguint(Plus, BigUint::new(vec!(1, 2, 3, 4, 5))).to_u64(),
-            None);
-
-        let max_value: BigUint = FromPrimitive::from_u64(u64::MAX).unwrap();
-        assert_eq!(BigInt::from_biguint(Minus, max_value).to_u64(), None);
-        assert_eq!(BigInt::from_biguint(Minus, BigUint::new(vec!(1, 2, 3, 4, 5))).to_u64(), None);
-    }
-
-    #[test]
-    fn test_convert_to_biguint() {
-        fn check(n: BigInt, ans_1: BigUint) {
-            assert_eq!(n.to_biguint().unwrap(), ans_1);
-            assert_eq!(n.to_biguint().unwrap().to_bigint().unwrap(), n);
-        }
-        let zero: BigInt = Zero::zero();
-        let unsigned_zero: BigUint = Zero::zero();
-        let positive = BigInt::from_biguint(
-            Plus, BigUint::new(vec!(1,2,3)));
-        let negative = -positive;
-
-        check(zero, unsigned_zero);
-        check(positive, BigUint::new(vec!(1,2,3)));
-
-        assert_eq!(negative.to_biguint(), None);
-    }
-
-    static SUM_TRIPLES: &'static [(&'static [BigDigit],
-                                   &'static [BigDigit],
-                                   &'static [BigDigit])] = &[
-        (&[],          &[],       &[]),
-        (&[],          &[ 1],     &[ 1]),
-        (&[ 1],        &[ 1],     &[ 2]),
-        (&[ 1],        &[ 1,  1], &[ 2,  1]),
-        (&[ 1],        &[-1],     &[ 0,  1]),
-        (&[ 1],        &[-1, -1], &[ 0,  0, 1]),
-        (&[-1, -1],    &[-1, -1], &[-2, -1, 1]),
-        (&[ 1,  1, 1], &[-1, -1], &[ 0,  1, 2]),
-        (&[ 2,  2, 1], &[-1, -2], &[ 1,  1, 2])
-    ];
-
-    #[test]
-    fn test_add() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(a + b == c);
-            assert!(b + a == c);
-            assert!(c + (-a) == b);
-            assert!(c + (-b) == a);
-            assert!(a + (-c) == (-b));
-            assert!(b + (-c) == (-a));
-            assert!((-a) + (-b) == (-c))
-            assert!(a + (-a) == Zero::zero());
-        }
-    }
-
-    #[test]
-    fn test_sub() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(c - a == b);
-            assert!(c - b == a);
-            assert!((-b) - a == (-c))
-            assert!((-a) - b == (-c))
-            assert!(b - (-a) == c);
-            assert!(a - (-b) == c);
-            assert!((-c) - (-a) == (-b));
-            assert!(a - a == Zero::zero());
-        }
-    }
-
-    static MUL_TRIPLES: &'static [(&'static [BigDigit],
-                                   &'static [BigDigit],
-                                   &'static [BigDigit])] = &[
-        (&[],               &[],               &[]),
-        (&[],               &[ 1],             &[]),
-        (&[ 2],             &[],               &[]),
-        (&[ 1],             &[ 1],             &[1]),
-        (&[ 2],             &[ 3],             &[ 6]),
-        (&[ 1],             &[ 1,  1,  1],     &[1, 1,  1]),
-        (&[ 1,  2,  3],     &[ 3],             &[ 3,  6,  9]),
-        (&[ 1,  1,  1],     &[-1],             &[-1, -1, -1]),
-        (&[ 1,  2,  3],     &[-1],             &[-1, -2, -2, 2]),
-        (&[ 1,  2,  3,  4], &[-1],             &[-1, -2, -2, -2, 3]),
-        (&[-1],             &[-1],             &[ 1, -2]),
-        (&[-1, -1],         &[-1],             &[ 1, -1, -2]),
-        (&[-1, -1, -1],     &[-1],             &[ 1, -1, -1, -2]),
-        (&[-1, -1, -1, -1], &[-1],             &[ 1, -1, -1, -1, -2]),
-        (&[-1/2 + 1],       &[ 2],             &[ 0,  1]),
-        (&[0, -1/2 + 1],    &[ 2],             &[ 0,  0,  1]),
-        (&[ 1,  2],         &[ 1,  2,  3],     &[1, 4,  7,  6]),
-        (&[-1, -1],         &[-1, -1, -1],     &[1, 0, -1, -2, -1]),
-        (&[-1, -1, -1],     &[-1, -1, -1, -1], &[1, 0,  0, -1, -2, -1, -1]),
-        (&[ 0,  0,  1],     &[ 1,  2,  3],     &[0, 0,  1,  2,  3]),
-        (&[ 0,  0,  1],     &[ 0,  0,  0,  1], &[0, 0,  0,  0,  0,  1])
-    ];
-
-    static DIV_REM_QUADRUPLES: &'static [(&'static [BigDigit],
-                                          &'static [BigDigit],
-                                          &'static [BigDigit],
-                                          &'static [BigDigit])]
-        = &[
-            (&[ 1],        &[ 2], &[],               &[1]),
-            (&[ 1,  1],    &[ 2], &[-1/2+1],         &[1]),
-            (&[ 1,  1, 1], &[ 2], &[-1/2+1, -1/2+1], &[1]),
-            (&[ 0,  1],    &[-1], &[1],              &[1]),
-            (&[-1, -1],    &[-2], &[2, 1],           &[3])
-        ];
-
-    #[test]
-    fn test_mul() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(a * b == c);
-            assert!(b * a == c);
-
-            assert!((-a) * b == -c);
-            assert!((-b) * a == -c);
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-            let d = BigInt::from_slice(Plus, d_vec);
-
-            assert!(a == b * c + d);
-            assert!(a == c * b + d);
-        }
-    }
-
-    #[test]
-    fn test_div_mod_floor() {
-        fn check_sub(a: &BigInt, b: &BigInt, ans_d: &BigInt, ans_m: &BigInt) {
-            let (d, m) = a.div_mod_floor(b);
-            if !m.is_zero() {
-                assert_eq!(m.sign, b.sign);
-            }
-            assert!(m.abs() <= b.abs());
-            assert!(*a == b * d + m);
-            assert!(d == *ans_d);
-            assert!(m == *ans_m);
-        }
-
-        fn check(a: &BigInt, b: &BigInt, d: &BigInt, m: &BigInt) {
-            if m.is_zero() {
-                check_sub(a, b, d, m);
-                check_sub(a, &b.neg(), &d.neg(), m);
-                check_sub(&a.neg(), b, &d.neg(), m);
-                check_sub(&a.neg(), &b.neg(), d, m);
-            } else {
-                check_sub(a, b, d, m);
-                check_sub(a, &b.neg(), &(d.neg() - One::one()), &(m - *b));
-                check_sub(&a.neg(), b, &(d.neg() - One::one()), &(b - *m));
-                check_sub(&a.neg(), &b.neg(), d, &m.neg());
-            }
-        }
-
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            if !a.is_zero() { check(&c, &a, &b, &Zero::zero()); }
-            if !b.is_zero() { check(&c, &b, &a, &Zero::zero()); }
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-            let d = BigInt::from_slice(Plus, d_vec);
-
-            if !b.is_zero() {
-                check(&a, &b, &c, &d);
-            }
-        }
-    }
-
-
-    #[test]
-    fn test_div_rem() {
-        fn check_sub(a: &BigInt, b: &BigInt, ans_q: &BigInt, ans_r: &BigInt) {
-            let (q, r) = a.div_rem(b);
-            if !r.is_zero() {
-                assert_eq!(r.sign, a.sign);
-            }
-            assert!(r.abs() <= b.abs());
-            assert!(*a == b * q + r);
-            assert!(q == *ans_q);
-            assert!(r == *ans_r);
-        }
-
-        fn check(a: &BigInt, b: &BigInt, q: &BigInt, r: &BigInt) {
-            check_sub(a, b, q, r);
-            check_sub(a, &b.neg(), &q.neg(), r);
-            check_sub(&a.neg(), b, &q.neg(), &r.neg());
-            check_sub(&a.neg(), &b.neg(), q, &r.neg());
-        }
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            if !a.is_zero() { check(&c, &a, &b, &Zero::zero()); }
-            if !b.is_zero() { check(&c, &b, &a, &Zero::zero()); }
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-            let d = BigInt::from_slice(Plus, d_vec);
-
-            if !b.is_zero() {
-                check(&a, &b, &c, &d);
-            }
-        }
-    }
-
-    #[test]
-    fn test_checked_add() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(a.checked_add(&b).unwrap() == c);
-            assert!(b.checked_add(&a).unwrap() == c);
-            assert!(c.checked_add(&(-a)).unwrap() == b);
-            assert!(c.checked_add(&(-b)).unwrap() == a);
-            assert!(a.checked_add(&(-c)).unwrap() == (-b));
-            assert!(b.checked_add(&(-c)).unwrap() == (-a));
-            assert!((-a).checked_add(&(-b)).unwrap() == (-c))
-            assert!(a.checked_add(&(-a)).unwrap() == Zero::zero());
-        }
-    }
-
-    #[test]
-    fn test_checked_sub() {
-        for elm in SUM_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(c.checked_sub(&a).unwrap() == b);
-            assert!(c.checked_sub(&b).unwrap() == a);
-            assert!((-b).checked_sub(&a).unwrap() == (-c))
-            assert!((-a).checked_sub(&b).unwrap() == (-c))
-            assert!(b.checked_sub(&(-a)).unwrap() == c);
-            assert!(a.checked_sub(&(-b)).unwrap() == c);
-            assert!((-c).checked_sub(&(-a)).unwrap() == (-b));
-            assert!(a.checked_sub(&a).unwrap() == Zero::zero());
-        }
-    }
-
-    #[test]
-    fn test_checked_mul() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            assert!(a.checked_mul(&b).unwrap() == c);
-            assert!(b.checked_mul(&a).unwrap() == c);
-
-            assert!((-a).checked_mul(&b).unwrap() == -c);
-            assert!((-b).checked_mul(&a).unwrap() == -c);
-        }
-
-        for elm in DIV_REM_QUADRUPLES.iter() {
-            let (a_vec, b_vec, c_vec, d_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-            let d = BigInt::from_slice(Plus, d_vec);
-
-            assert!(a == b.checked_mul(&c).unwrap() + d);
-            assert!(a == c.checked_mul(&b).unwrap() + d);
-        }
-    }
-    #[test]
-    fn test_checked_div() {
-        for elm in MUL_TRIPLES.iter() {
-            let (a_vec, b_vec, c_vec) = *elm;
-            let a = BigInt::from_slice(Plus, a_vec);
-            let b = BigInt::from_slice(Plus, b_vec);
-            let c = BigInt::from_slice(Plus, c_vec);
-
-            if !a.is_zero() {
-                assert!(c.checked_div(&a).unwrap() == b);
-                assert!((-c).checked_div(&(-a)).unwrap() == b);
-                assert!((-c).checked_div(&a).unwrap() == -b);
-            }
-            if !b.is_zero() {
-                assert!(c.checked_div(&b).unwrap() == a);
-                assert!((-c).checked_div(&(-b)).unwrap() == a);
-                assert!((-c).checked_div(&b).unwrap() == -a);
-            }
-
-            assert!(c.checked_div(&Zero::zero()).is_none());
-            assert!((-c).checked_div(&Zero::zero()).is_none());
-        }
-    }
-
-    #[test]
-    fn test_gcd() {
-        fn check(a: int, b: int, c: int) {
-            let big_a: BigInt = FromPrimitive::from_int(a).unwrap();
-            let big_b: BigInt = FromPrimitive::from_int(b).unwrap();
-            let big_c: BigInt = FromPrimitive::from_int(c).unwrap();
-
-            assert_eq!(big_a.gcd(&big_b), big_c);
-        }
-
-        check(10, 2, 2);
-        check(10, 3, 1);
-        check(0, 3, 3);
-        check(3, 3, 3);
-        check(56, 42, 14);
-        check(3, -3, 3);
-        check(-6, 3, 3);
-        check(-4, -2, 2);
-    }
-
-    #[test]
-    fn test_lcm() {
-        fn check(a: int, b: int, c: int) {
-            let big_a: BigInt = FromPrimitive::from_int(a).unwrap();
-            let big_b: BigInt = FromPrimitive::from_int(b).unwrap();
-            let big_c: BigInt = FromPrimitive::from_int(c).unwrap();
-
-            assert_eq!(big_a.lcm(&big_b), big_c);
-        }
-
-        check(1, 0, 0);
-        check(0, 1, 0);
-        check(1, 1, 1);
-        check(-1, 1, 1);
-        check(1, -1, 1);
-        check(-1, -1, 1);
-        check(8, 9, 72);
-        check(11, 5, 55);
-    }
-
-    #[test]
-    fn test_abs_sub() {
-        let zero: BigInt = Zero::zero();
-        let one: BigInt = One::one();
-        assert_eq!((-one).abs_sub(&one), zero);
-        let one: BigInt = One::one();
-        let zero: BigInt = Zero::zero();
-        assert_eq!(one.abs_sub(&one), zero);
-        let one: BigInt = One::one();
-        let zero: BigInt = Zero::zero();
-        assert_eq!(one.abs_sub(&zero), one);
-        let one: BigInt = One::one();
-        let two: BigInt = FromPrimitive::from_int(2).unwrap();
-        assert_eq!(one.abs_sub(&-one), two);
-    }
-
-    #[test]
-    fn test_to_str_radix() {
-        fn check(n: int, ans: &str) {
-            let n: BigInt = FromPrimitive::from_int(n).unwrap();
-            assert!(ans == n.to_str_radix(10).as_slice());
-        }
-        check(10, "10");
-        check(1, "1");
-        check(0, "0");
-        check(-1, "-1");
-        check(-10, "-10");
-    }
-
-
-    #[test]
-    fn test_from_str_radix() {
-        fn check(s: &str, ans: Option<int>) {
-            let ans = ans.map(|n| {
-                let x: BigInt = FromPrimitive::from_int(n).unwrap();
-                x
-            });
-            assert_eq!(FromStrRadix::from_str_radix(s, 10), ans);
-        }
-        check("10", Some(10));
-        check("1", Some(1));
-        check("0", Some(0));
-        check("-1", Some(-1));
-        check("-10", Some(-10));
-        check("Z", None);
-        check("_", None);
-
-        // issue 10522, this hit an edge case that caused it to
-        // attempt to allocate a vector of size (-1u) == huge.
-        let x: BigInt =
-            from_str(format!("1{}", "0".repeat(36)).as_slice()).unwrap();
-        let _y = x.to_string();
-    }
-
-    #[test]
-    fn test_neg() {
-        assert!(-BigInt::new(Plus,  vec!(1, 1, 1)) ==
-            BigInt::new(Minus, vec!(1, 1, 1)));
-        assert!(-BigInt::new(Minus, vec!(1, 1, 1)) ==
-            BigInt::new(Plus,  vec!(1, 1, 1)));
-        let zero: BigInt = Zero::zero();
-        assert_eq!(-zero, zero);
-    }
-
-    #[test]
-    fn test_rand() {
-        let mut rng = task_rng();
-        let _n: BigInt = rng.gen_bigint(137);
-        assert!(rng.gen_bigint(0).is_zero());
-    }
-
-    #[test]
-    fn test_rand_range() {
-        let mut rng = task_rng();
-
-        for _ in range(0u, 10) {
-            assert_eq!(rng.gen_bigint_range(&FromPrimitive::from_uint(236).unwrap(),
-                                            &FromPrimitive::from_uint(237).unwrap()),
-                       FromPrimitive::from_uint(236).unwrap());
-        }
-
-        fn check(l: BigInt, u: BigInt) {
-            let mut rng = task_rng();
-            for _ in range(0u, 1000) {
-                let n: BigInt = rng.gen_bigint_range(&l, &u);
-                assert!(n >= l);
-                assert!(n < u);
-            }
-        }
-        let l: BigInt = FromPrimitive::from_uint(403469000 + 2352).unwrap();
-        let u: BigInt = FromPrimitive::from_uint(403469000 + 3513).unwrap();
-        check( l.clone(),  u.clone());
-        check(-l.clone(),  u.clone());
-        check(-u.clone(), -l.clone());
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_zero_rand_range() {
-        task_rng().gen_bigint_range(&FromPrimitive::from_int(54).unwrap(),
-                                    &FromPrimitive::from_int(54).unwrap());
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_negative_rand_range() {
-        let mut rng = task_rng();
-        let l = FromPrimitive::from_uint(2352).unwrap();
-        let u = FromPrimitive::from_uint(3513).unwrap();
-        // Switching u and l should fail:
-        let _n: BigInt = rng.gen_bigint_range(&u, &l);
-    }
-}
-
-#[cfg(test)]
-mod bench {
-    extern crate test;
-    use self::test::Bencher;
-    use super::BigUint;
-    use std::iter;
-    use std::mem::replace;
-    use std::num::{FromPrimitive, Zero, One};
-
-    fn factorial(n: uint) -> BigUint {
-        let mut f: BigUint = One::one();
-        for i in iter::range_inclusive(1, n) {
-            f = f * FromPrimitive::from_uint(i).unwrap();
-        }
-        f
-    }
-
-    fn fib(n: uint) -> BigUint {
-        let mut f0: BigUint = Zero::zero();
-        let mut f1: BigUint = One::one();
-        for _ in range(0, n) {
-            let f2 = f0 + f1;
-            f0 = replace(&mut f1, f2);
-        }
-        f0
-    }
-
-    #[bench]
-    fn factorial_100(b: &mut Bencher) {
-        b.iter(|| {
-            factorial(100);
-        });
-    }
-
-    #[bench]
-    fn fib_100(b: &mut Bencher) {
-        b.iter(|| {
-            fib(100);
-        });
-    }
-
-    #[bench]
-    fn to_string(b: &mut Bencher) {
-        let fac = factorial(100);
-        let fib = fib(100);
-        b.iter(|| {
-            fac.to_string();
-        });
-        b.iter(|| {
-            fib.to_string();
-        });
-    }
-
-    #[bench]
-    fn shr(b: &mut Bencher) {
-        let n = { let one : BigUint = One::one(); one << 1000 };
-        b.iter(|| {
-            let mut m = n.clone();
-            for _ in range(0u, 10) {
-                m = m >> 1;
-            }
-        })
-    }
-}
diff --git a/src/libnum/complex.rs b/src/libnum/complex.rs
deleted file mode 100644
index 6690b1d5ddc..00000000000
--- a/src/libnum/complex.rs
+++ /dev/null
@@ -1,379 +0,0 @@
-// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-
-//! Complex numbers.
-
-use std::fmt;
-use std::num::{Zero, One, ToStrRadix};
-
-// FIXME #1284: handle complex NaN & infinity etc. This
-// probably doesn't map to C's _Complex correctly.
-
-/// A complex number in Cartesian form.
-#[deriving(PartialEq, Clone, Hash)]
-pub struct Complex<T> {
-    /// Real portion of the complex number
-    pub re: T,
-    /// Imaginary portion of the complex number
-    pub im: T
-}
-
-pub type Complex32 = Complex<f32>;
-pub type Complex64 = Complex<f64>;
-
-impl<T: Clone + Num> Complex<T> {
-    /// Create a new Complex
-    #[inline]
-    pub fn new(re: T, im: T) -> Complex<T> {
-        Complex { re: re, im: im }
-    }
-
-    /// Returns the square of the norm (since `T` doesn't necessarily
-    /// have a sqrt function), i.e. `re^2 + im^2`.
-    #[inline]
-    pub fn norm_sqr(&self) -> T {
-        self.re * self.re + self.im * self.im
-    }
-
-
-    /// Returns the complex conjugate. i.e. `re - i im`
-    #[inline]
-    pub fn conj(&self) -> Complex<T> {
-        Complex::new(self.re.clone(), -self.im)
-    }
-
-
-    /// Multiplies `self` by the scalar `t`.
-    #[inline]
-    pub fn scale(&self, t: T) -> Complex<T> {
-        Complex::new(self.re * t, self.im * t)
-    }
-
-    /// Divides `self` by the scalar `t`.
-    #[inline]
-    pub fn unscale(&self, t: T) -> Complex<T> {
-        Complex::new(self.re / t, self.im / t)
-    }
-
-    /// Returns `1/self`
-    #[inline]
-    pub fn inv(&self) -> Complex<T> {
-        let norm_sqr = self.norm_sqr();
-        Complex::new(self.re / norm_sqr,
-                    -self.im / norm_sqr)
-    }
-}
-
-impl<T: Clone + FloatMath> Complex<T> {
-    /// Calculate |self|
-    #[inline]
-    pub fn norm(&self) -> T {
-        self.re.hypot(self.im)
-    }
-}
-
-impl<T: Clone + FloatMath> Complex<T> {
-    /// Calculate the principal Arg of self.
-    #[inline]
-    pub fn arg(&self) -> T {
-        self.im.atan2(self.re)
-    }
-    /// Convert to polar form (r, theta), such that `self = r * exp(i
-    /// * theta)`
-    #[inline]
-    pub fn to_polar(&self) -> (T, T) {
-        (self.norm(), self.arg())
-    }
-    /// Convert a polar representation into a complex number.
-    #[inline]
-    pub fn from_polar(r: &T, theta: &T) -> Complex<T> {
-        Complex::new(*r * theta.cos(), *r * theta.sin())
-    }
-}
-
-/* arithmetic */
-// (a + i b) + (c + i d) == (a + c) + i (b + d)
-impl<T: Clone + Num> Add<Complex<T>, Complex<T>> for Complex<T> {
-    #[inline]
-    fn add(&self, other: &Complex<T>) -> Complex<T> {
-        Complex::new(self.re + other.re, self.im + other.im)
-    }
-}
-// (a + i b) - (c + i d) == (a - c) + i (b - d)
-impl<T: Clone + Num> Sub<Complex<T>, Complex<T>> for Complex<T> {
-    #[inline]
-    fn sub(&self, other: &Complex<T>) -> Complex<T> {
-        Complex::new(self.re - other.re, self.im - other.im)
-    }
-}
-// (a + i b) * (c + i d) == (a*c - b*d) + i (a*d + b*c)
-impl<T: Clone + Num> Mul<Complex<T>, Complex<T>> for Complex<T> {
-    #[inline]
-    fn mul(&self, other: &Complex<T>) -> Complex<T> {
-        Complex::new(self.re*other.re - self.im*other.im,
-                   self.re*other.im + self.im*other.re)
-    }
-}
-
-// (a + i b) / (c + i d) == [(a + i b) * (c - i d)] / (c*c + d*d)
-//   == [(a*c + b*d) / (c*c + d*d)] + i [(b*c - a*d) / (c*c + d*d)]
-impl<T: Clone + Num> Div<Complex<T>, Complex<T>> for Complex<T> {
-    #[inline]
-    fn div(&self, other: &Complex<T>) -> Complex<T> {
-        let norm_sqr = other.norm_sqr();
-        Complex::new((self.re*other.re + self.im*other.im) / norm_sqr,
-                   (self.im*other.re - self.re*other.im) / norm_sqr)
-    }
-}
-
-impl<T: Clone + Num> Neg<Complex<T>> for Complex<T> {
-    #[inline]
-    fn neg(&self) -> Complex<T> {
-        Complex::new(-self.re, -self.im)
-    }
-}
-
-/* constants */
-impl<T: Clone + Num> Zero for Complex<T> {
-    #[inline]
-    fn zero() -> Complex<T> {
-        Complex::new(Zero::zero(), Zero::zero())
-    }
-
-    #[inline]
-    fn is_zero(&self) -> bool {
-        self.re.is_zero() && self.im.is_zero()
-    }
-}
-
-impl<T: Clone + Num> One for Complex<T> {
-    #[inline]
-    fn one() -> Complex<T> {
-        Complex::new(One::one(), Zero::zero())
-    }
-}
-
-/* string conversions */
-impl<T: fmt::Show + Num + PartialOrd> fmt::Show for Complex<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if self.im < Zero::zero() {
-            write!(f, "{}-{}i", self.re, -self.im)
-        } else {
-            write!(f, "{}+{}i", self.re, self.im)
-        }
-    }
-}
-
-impl<T: ToStrRadix + Num + PartialOrd> ToStrRadix for Complex<T> {
-    fn to_str_radix(&self, radix: uint) -> String {
-        if self.im < Zero::zero() {
-            format!("{}-{}i",
-                    self.re.to_str_radix(radix),
-                    (-self.im).to_str_radix(radix))
-        } else {
-            format!("{}+{}i",
-                    self.re.to_str_radix(radix),
-                    self.im.to_str_radix(radix))
-        }
-    }
-}
-
-#[cfg(test)]
-mod test {
-    #![allow(non_uppercase_statics)]
-
-    use super::{Complex64, Complex};
-    use std::num::{Zero, One, Float};
-    use std::hash::hash;
-
-    pub const _0_0i : Complex64 = Complex { re: 0.0, im: 0.0 };
-    pub const _1_0i : Complex64 = Complex { re: 1.0, im: 0.0 };
-    pub const _1_1i : Complex64 = Complex { re: 1.0, im: 1.0 };
-    pub const _0_1i : Complex64 = Complex { re: 0.0, im: 1.0 };
-    pub const _neg1_1i : Complex64 = Complex { re: -1.0, im: 1.0 };
-    pub const _05_05i : Complex64 = Complex { re: 0.5, im: 0.5 };
-    pub const all_consts : [Complex64, .. 5] = [_0_0i, _1_0i, _1_1i, _neg1_1i, _05_05i];
-
-    #[test]
-    fn test_consts() {
-        // check our constants are what Complex::new creates
-        fn test(c : Complex64, r : f64, i: f64) {
-            assert_eq!(c, Complex::new(r,i));
-        }
-        test(_0_0i, 0.0, 0.0);
-        test(_1_0i, 1.0, 0.0);
-        test(_1_1i, 1.0, 1.0);
-        test(_neg1_1i, -1.0, 1.0);
-        test(_05_05i, 0.5, 0.5);
-
-        assert_eq!(_0_0i, Zero::zero());
-        assert_eq!(_1_0i, One::one());
-    }
-
-    #[test]
-    #[cfg_attr(target_arch = "x86", ignore)]
-    // FIXME #7158: (maybe?) currently failing on x86.
-    fn test_norm() {
-        fn test(c: Complex64, ns: f64) {
-            assert_eq!(c.norm_sqr(), ns);
-            assert_eq!(c.norm(), ns.sqrt())
-        }
-        test(_0_0i, 0.0);
-        test(_1_0i, 1.0);
-        test(_1_1i, 2.0);
-        test(_neg1_1i, 2.0);
-        test(_05_05i, 0.5);
-    }
-
-    #[test]
-    fn test_scale_unscale() {
-        assert_eq!(_05_05i.scale(2.0), _1_1i);
-        assert_eq!(_1_1i.unscale(2.0), _05_05i);
-        for &c in all_consts.iter() {
-            assert_eq!(c.scale(2.0).unscale(2.0), c);
-        }
-    }
-
-    #[test]
-    fn test_conj() {
-        for &c in all_consts.iter() {
-            assert_eq!(c.conj(), Complex::new(c.re, -c.im));
-            assert_eq!(c.conj().conj(), c);
-        }
-    }
-
-    #[test]
-    fn test_inv() {
-        assert_eq!(_1_1i.inv(), _05_05i.conj());
-        assert_eq!(_1_0i.inv(), _1_0i.inv());
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_divide_by_zero_natural() {
-        let n = Complex::new(2i, 3i);
-        let d = Complex::new(0, 0);
-        let _x = n / d;
-    }
-
-    #[test]
-    #[should_fail]
-    #[ignore]
-    fn test_inv_zero() {
-        // FIXME #5736: should this really fail, or just NaN?
-        _0_0i.inv();
-    }
-
-    #[test]
-    fn test_arg() {
-        fn test(c: Complex64, arg: f64) {
-            assert!((c.arg() - arg).abs() < 1.0e-6)
-        }
-        test(_1_0i, 0.0);
-        test(_1_1i, 0.25 * Float::pi());
-        test(_neg1_1i, 0.75 * Float::pi());
-        test(_05_05i, 0.25 * Float::pi());
-    }
-
-    #[test]
-    fn test_polar_conv() {
-        fn test(c: Complex64) {
-            let (r, theta) = c.to_polar();
-            assert!((c - Complex::from_polar(&r, &theta)).norm() < 1e-6);
-        }
-        for &c in all_consts.iter() { test(c); }
-    }
-
-    mod arith {
-        use super::{_0_0i, _1_0i, _1_1i, _0_1i, _neg1_1i, _05_05i, all_consts};
-        use std::num::Zero;
-
-        #[test]
-        fn test_add() {
-            assert_eq!(_05_05i + _05_05i, _1_1i);
-            assert_eq!(_0_1i + _1_0i, _1_1i);
-            assert_eq!(_1_0i + _neg1_1i, _0_1i);
-
-            for &c in all_consts.iter() {
-                assert_eq!(_0_0i + c, c);
-                assert_eq!(c + _0_0i, c);
-            }
-        }
-
-        #[test]
-        fn test_sub() {
-            assert_eq!(_05_05i - _05_05i, _0_0i);
-            assert_eq!(_0_1i - _1_0i, _neg1_1i);
-            assert_eq!(_0_1i - _neg1_1i, _1_0i);
-
-            for &c in all_consts.iter() {
-                assert_eq!(c - _0_0i, c);
-                assert_eq!(c - c, _0_0i);
-            }
-        }
-
-        #[test]
-        fn test_mul() {
-            assert_eq!(_05_05i * _05_05i, _0_1i.unscale(2.0));
-            assert_eq!(_1_1i * _0_1i, _neg1_1i);
-
-            // i^2 & i^4
-            assert_eq!(_0_1i * _0_1i, -_1_0i);
-            assert_eq!(_0_1i * _0_1i * _0_1i * _0_1i, _1_0i);
-
-            for &c in all_consts.iter() {
-                assert_eq!(c * _1_0i, c);
-                assert_eq!(_1_0i * c, c);
-            }
-        }
-        #[test]
-        fn test_div() {
-            assert_eq!(_neg1_1i / _0_1i, _1_1i);
-            for &c in all_consts.iter() {
-                if c != Zero::zero() {
-                    assert_eq!(c / c, _1_0i);
-                }
-            }
-        }
-        #[test]
-        fn test_neg() {
-            assert_eq!(-_1_0i + _0_1i, _neg1_1i);
-            assert_eq!((-_0_1i) * _0_1i, _1_0i);
-            for &c in all_consts.iter() {
-                assert_eq!(-(-c), c);
-            }
-        }
-    }
-
-    #[test]
-    fn test_to_string() {
-        fn test(c : Complex64, s: String) {
-            assert_eq!(c.to_string(), s);
-        }
-        test(_0_0i, "0+0i".to_string());
-        test(_1_0i, "1+0i".to_string());
-        test(_0_1i, "0+1i".to_string());
-        test(_1_1i, "1+1i".to_string());
-        test(_neg1_1i, "-1+1i".to_string());
-        test(-_neg1_1i, "1-1i".to_string());
-        test(_05_05i, "0.5+0.5i".to_string());
-    }
-
-    #[test]
-    fn test_hash() {
-        let a = Complex::new(0i32, 0i32);
-        let b = Complex::new(1i32, 0i32);
-        let c = Complex::new(0i32, 1i32);
-        assert!(hash(&a) != hash(&b));
-        assert!(hash(&b) != hash(&c));
-        assert!(hash(&c) != hash(&a));
-    }
-}
diff --git a/src/libnum/integer.rs b/src/libnum/integer.rs
deleted file mode 100644
index c5d076a70b5..00000000000
--- a/src/libnum/integer.rs
+++ /dev/null
@@ -1,507 +0,0 @@
-// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Integer trait and functions.
-
-pub trait Integer: Num + PartialOrd
-                 + Div<Self, Self>
-                 + Rem<Self, Self> {
-    /// Floored integer division.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert!(( 8i).div_floor(& 3) ==  2);
-    /// assert!(( 8i).div_floor(&-3) == -3);
-    /// assert!((-8i).div_floor(& 3) == -3);
-    /// assert!((-8i).div_floor(&-3) ==  2);
-    ///
-    /// assert!(( 1i).div_floor(& 2) ==  0);
-    /// assert!(( 1i).div_floor(&-2) == -1);
-    /// assert!((-1i).div_floor(& 2) == -1);
-    /// assert!((-1i).div_floor(&-2) ==  0);
-    /// ```
-    fn div_floor(&self, other: &Self) -> Self;
-
-    /// Floored integer modulo, satisfying:
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// # let n = 1i; let d = 1i;
-    /// assert!(n.div_floor(&d) * d + n.mod_floor(&d) == n)
-    /// ```
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert!(( 8i).mod_floor(& 3) ==  2);
-    /// assert!(( 8i).mod_floor(&-3) == -1);
-    /// assert!((-8i).mod_floor(& 3) ==  1);
-    /// assert!((-8i).mod_floor(&-3) == -2);
-    ///
-    /// assert!(( 1i).mod_floor(& 2) ==  1);
-    /// assert!(( 1i).mod_floor(&-2) == -1);
-    /// assert!((-1i).mod_floor(& 2) ==  1);
-    /// assert!((-1i).mod_floor(&-2) == -1);
-    /// ```
-    fn mod_floor(&self, other: &Self) -> Self;
-
-    /// Greatest Common Divisor (GCD).
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(6i.gcd(&8), 2);
-    /// assert_eq!(7i.gcd(&3), 1);
-    /// ```
-    fn gcd(&self, other: &Self) -> Self;
-
-    /// Lowest Common Multiple (LCM).
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(7i.lcm(&3), 21);
-    /// assert_eq!(2i.lcm(&4), 4);
-    /// ```
-    fn lcm(&self, other: &Self) -> Self;
-
-    /// Deprecated, use `is_multiple_of` instead.
-    #[deprecated = "function renamed to `is_multiple_of`"]
-    fn divides(&self, other: &Self) -> bool;
-
-    /// Returns `true` if `other` is a multiple of `self`.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(9i.is_multiple_of(&3), true);
-    /// assert_eq!(3i.is_multiple_of(&9), false);
-    /// ```
-    fn is_multiple_of(&self, other: &Self) -> bool;
-
-    /// Returns `true` if the number is even.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(3i.is_even(), false);
-    /// assert_eq!(4i.is_even(), true);
-    /// ```
-    fn is_even(&self) -> bool;
-
-    /// Returns `true` if the number is odd.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(3i.is_odd(), true);
-    /// assert_eq!(4i.is_odd(), false);
-    /// ```
-    fn is_odd(&self) -> bool;
-
-    /// Simultaneous truncated integer division and modulus.
-    /// Returns `(quotient, remainder)`.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(( 8i).div_rem( &3), ( 2,  2));
-    /// assert_eq!(( 8i).div_rem(&-3), (-2,  2));
-    /// assert_eq!((-8i).div_rem( &3), (-2, -2));
-    /// assert_eq!((-8i).div_rem(&-3), ( 2, -2));
-    ///
-    /// assert_eq!(( 1i).div_rem( &2), ( 0,  1));
-    /// assert_eq!(( 1i).div_rem(&-2), ( 0,  1));
-    /// assert_eq!((-1i).div_rem( &2), ( 0, -1));
-    /// assert_eq!((-1i).div_rem(&-2), ( 0, -1));
-    /// ```
-    #[inline]
-    fn div_rem(&self, other: &Self) -> (Self, Self) {
-        (*self / *other, *self % *other)
-    }
-
-    /// Simultaneous floored integer division and modulus.
-    /// Returns `(quotient, remainder)`.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # #![allow(deprecated)]
-    /// # use num::Integer;
-    /// assert_eq!(( 8i).div_mod_floor( &3), ( 2,  2));
-    /// assert_eq!(( 8i).div_mod_floor(&-3), (-3, -1));
-    /// assert_eq!((-8i).div_mod_floor( &3), (-3,  1));
-    /// assert_eq!((-8i).div_mod_floor(&-3), ( 2, -2));
-    ///
-    /// assert_eq!(( 1i).div_mod_floor( &2), ( 0,  1));
-    /// assert_eq!(( 1i).div_mod_floor(&-2), (-1, -1));
-    /// assert_eq!((-1i).div_mod_floor( &2), (-1,  1));
-    /// assert_eq!((-1i).div_mod_floor(&-2), ( 0, -1));
-    /// ```
-    fn div_mod_floor(&self, other: &Self) -> (Self, Self) {
-        (self.div_floor(other), self.mod_floor(other))
-    }
-}
-
-/// Simultaneous integer division and modulus
-#[inline] pub fn div_rem<T: Integer>(x: T, y: T) -> (T, T) { x.div_rem(&y) }
-/// Floored integer division
-#[inline] pub fn div_floor<T: Integer>(x: T, y: T) -> T { x.div_floor(&y) }
-/// Floored integer modulus
-#[inline] pub fn mod_floor<T: Integer>(x: T, y: T) -> T { x.mod_floor(&y) }
-/// Simultaneous floored integer division and modulus
-#[inline] pub fn div_mod_floor<T: Integer>(x: T, y: T) -> (T, T) { x.div_mod_floor(&y) }
-
-/// Calculates the Greatest Common Divisor (GCD) of the number and `other`. The
-/// result is always positive.
-#[inline(always)] pub fn gcd<T: Integer>(x: T, y: T) -> T { x.gcd(&y) }
-/// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
-#[inline(always)] pub fn lcm<T: Integer>(x: T, y: T) -> T { x.lcm(&y) }
-
-macro_rules! impl_integer_for_int {
-    ($T:ty, $test_mod:ident) => (
-        impl Integer for $T {
-            /// Floored integer division
-            #[inline]
-            fn div_floor(&self, other: &$T) -> $T {
-                // Algorithm from [Daan Leijen. _Division and Modulus for Computer Scientists_,
-                // December 2001](http://research.microsoft.com/pubs/151917/divmodnote-letter.pdf)
-                match self.div_rem(other) {
-                    (d, r) if (r > 0 && *other < 0)
-                           || (r < 0 && *other > 0) => d - 1,
-                    (d, _)                          => d,
-                }
-            }
-
-            /// Floored integer modulo
-            #[inline]
-            fn mod_floor(&self, other: &$T) -> $T {
-                // Algorithm from [Daan Leijen. _Division and Modulus for Computer Scientists_,
-                // December 2001](http://research.microsoft.com/pubs/151917/divmodnote-letter.pdf)
-                match *self % *other {
-                    r if (r > 0 && *other < 0)
-                      || (r < 0 && *other > 0) => r + *other,
-                    r                          => r,
-                }
-            }
-
-            /// Calculates `div_floor` and `mod_floor` simultaneously
-            #[inline]
-            fn div_mod_floor(&self, other: &$T) -> ($T,$T) {
-                // Algorithm from [Daan Leijen. _Division and Modulus for Computer Scientists_,
-                // December 2001](http://research.microsoft.com/pubs/151917/divmodnote-letter.pdf)
-                match self.div_rem(other) {
-                    (d, r) if (r > 0 && *other < 0)
-                           || (r < 0 && *other > 0) => (d - 1, r + *other),
-                    (d, r)                          => (d, r),
-                }
-            }
-
-            /// Calculates the Greatest Common Divisor (GCD) of the number and
-            /// `other`. The result is always positive.
-            #[inline]
-            fn gcd(&self, other: &$T) -> $T {
-                // Use Euclid's algorithm
-                let mut m = *self;
-                let mut n = *other;
-                while m != 0 {
-                    let temp = m;
-                    m = n % temp;
-                    n = temp;
-                }
-                n.abs()
-            }
-
-            /// Calculates the Lowest Common Multiple (LCM) of the number and
-            /// `other`.
-            #[inline]
-            fn lcm(&self, other: &$T) -> $T {
-                // should not have to recalculate abs
-                ((*self * *other) / self.gcd(other)).abs()
-            }
-
-            /// Deprecated, use `is_multiple_of` instead.
-            #[deprecated = "function renamed to `is_multiple_of`"]
-            #[inline]
-            fn divides(&self, other: &$T) -> bool { return self.is_multiple_of(other); }
-
-            /// Returns `true` if the number is a multiple of `other`.
-            #[inline]
-            fn is_multiple_of(&self, other: &$T) -> bool { *self % *other == 0 }
-
-            /// Returns `true` if the number is divisible by `2`
-            #[inline]
-            fn is_even(&self) -> bool { self & 1 == 0 }
-
-            /// Returns `true` if the number is not divisible by `2`
-            #[inline]
-            fn is_odd(&self) -> bool { !self.is_even() }
-        }
-
-        #[cfg(test)]
-        mod $test_mod {
-            use Integer;
-
-            /// Checks that the division rule holds for:
-            ///
-            /// - `n`: numerator (dividend)
-            /// - `d`: denominator (divisor)
-            /// - `qr`: quotient and remainder
-            #[cfg(test)]
-            fn test_division_rule((n,d): ($T,$T), (q,r): ($T,$T)) {
-                assert_eq!(d * q + r, n);
-            }
-
-            #[test]
-            fn test_div_rem() {
-                fn test_nd_dr(nd: ($T,$T), qr: ($T,$T)) {
-                    let (n,d) = nd;
-                    let separate_div_rem = (n / d, n % d);
-                    let combined_div_rem = n.div_rem(&d);
-
-                    assert_eq!(separate_div_rem, qr);
-                    assert_eq!(combined_div_rem, qr);
-
-                    test_division_rule(nd, separate_div_rem);
-                    test_division_rule(nd, combined_div_rem);
-                }
-
-                test_nd_dr(( 8,  3), ( 2,  2));
-                test_nd_dr(( 8, -3), (-2,  2));
-                test_nd_dr((-8,  3), (-2, -2));
-                test_nd_dr((-8, -3), ( 2, -2));
-
-                test_nd_dr(( 1,  2), ( 0,  1));
-                test_nd_dr(( 1, -2), ( 0,  1));
-                test_nd_dr((-1,  2), ( 0, -1));
-                test_nd_dr((-1, -2), ( 0, -1));
-            }
-
-            #[test]
-            fn test_div_mod_floor() {
-                fn test_nd_dm(nd: ($T,$T), dm: ($T,$T)) {
-                    let (n,d) = nd;
-                    let separate_div_mod_floor = (n.div_floor(&d), n.mod_floor(&d));
-                    let combined_div_mod_floor = n.div_mod_floor(&d);
-
-                    assert_eq!(separate_div_mod_floor, dm);
-                    assert_eq!(combined_div_mod_floor, dm);
-
-                    test_division_rule(nd, separate_div_mod_floor);
-                    test_division_rule(nd, combined_div_mod_floor);
-                }
-
-                test_nd_dm(( 8,  3), ( 2,  2));
-                test_nd_dm(( 8, -3), (-3, -1));
-                test_nd_dm((-8,  3), (-3,  1));
-                test_nd_dm((-8, -3), ( 2, -2));
-
-                test_nd_dm(( 1,  2), ( 0,  1));
-                test_nd_dm(( 1, -2), (-1, -1));
-                test_nd_dm((-1,  2), (-1,  1));
-                test_nd_dm((-1, -2), ( 0, -1));
-            }
-
-            #[test]
-            fn test_gcd() {
-                assert_eq!((10 as $T).gcd(&2), 2 as $T);
-                assert_eq!((10 as $T).gcd(&3), 1 as $T);
-                assert_eq!((0 as $T).gcd(&3), 3 as $T);
-                assert_eq!((3 as $T).gcd(&3), 3 as $T);
-                assert_eq!((56 as $T).gcd(&42), 14 as $T);
-                assert_eq!((3 as $T).gcd(&-3), 3 as $T);
-                assert_eq!((-6 as $T).gcd(&3), 3 as $T);
-                assert_eq!((-4 as $T).gcd(&-2), 2 as $T);
-            }
-
-            #[test]
-            fn test_lcm() {
-                assert_eq!((1 as $T).lcm(&0), 0 as $T);
-                assert_eq!((0 as $T).lcm(&1), 0 as $T);
-                assert_eq!((1 as $T).lcm(&1), 1 as $T);
-                assert_eq!((-1 as $T).lcm(&1), 1 as $T);
-                assert_eq!((1 as $T).lcm(&-1), 1 as $T);
-                assert_eq!((-1 as $T).lcm(&-1), 1 as $T);
-                assert_eq!((8 as $T).lcm(&9), 72 as $T);
-                assert_eq!((11 as $T).lcm(&5), 55 as $T);
-            }
-
-            #[test]
-            fn test_even() {
-                assert_eq!((-4 as $T).is_even(), true);
-                assert_eq!((-3 as $T).is_even(), false);
-                assert_eq!((-2 as $T).is_even(), true);
-                assert_eq!((-1 as $T).is_even(), false);
-                assert_eq!((0 as $T).is_even(), true);
-                assert_eq!((1 as $T).is_even(), false);
-                assert_eq!((2 as $T).is_even(), true);
-                assert_eq!((3 as $T).is_even(), false);
-                assert_eq!((4 as $T).is_even(), true);
-            }
-
-            #[test]
-            fn test_odd() {
-                assert_eq!((-4 as $T).is_odd(), false);
-                assert_eq!((-3 as $T).is_odd(), true);
-                assert_eq!((-2 as $T).is_odd(), false);
-                assert_eq!((-1 as $T).is_odd(), true);
-                assert_eq!((0 as $T).is_odd(), false);
-                assert_eq!((1 as $T).is_odd(), true);
-                assert_eq!((2 as $T).is_odd(), false);
-                assert_eq!((3 as $T).is_odd(), true);
-                assert_eq!((4 as $T).is_odd(), false);
-            }
-        }
-    )
-}
-
-impl_integer_for_int!(i8,   test_integer_i8)
-impl_integer_for_int!(i16,  test_integer_i16)
-impl_integer_for_int!(i32,  test_integer_i32)
-impl_integer_for_int!(i64,  test_integer_i64)
-impl_integer_for_int!(int,  test_integer_int)
-
-macro_rules! impl_integer_for_uint {
-    ($T:ty, $test_mod:ident) => (
-        impl Integer for $T {
-            /// Unsigned integer division. Returns the same result as `div` (`/`).
-            #[inline]
-            fn div_floor(&self, other: &$T) -> $T { *self / *other }
-
-            /// Unsigned integer modulo operation. Returns the same result as `rem` (`%`).
-            #[inline]
-            fn mod_floor(&self, other: &$T) -> $T { *self % *other }
-
-            /// Calculates the Greatest Common Divisor (GCD) of the number and `other`
-            #[inline]
-            fn gcd(&self, other: &$T) -> $T {
-                // Use Euclid's algorithm
-                let mut m = *self;
-                let mut n = *other;
-                while m != 0 {
-                    let temp = m;
-                    m = n % temp;
-                    n = temp;
-                }
-                n
-            }
-
-            /// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
-            #[inline]
-            fn lcm(&self, other: &$T) -> $T {
-                (*self * *other) / self.gcd(other)
-            }
-
-            /// Deprecated, use `is_multiple_of` instead.
-            #[deprecated = "function renamed to `is_multiple_of`"]
-            #[inline]
-            fn divides(&self, other: &$T) -> bool { return self.is_multiple_of(other); }
-
-            /// Returns `true` if the number is a multiple of `other`.
-            #[inline]
-            fn is_multiple_of(&self, other: &$T) -> bool { *self % *other == 0 }
-
-            /// Returns `true` if the number is divisible by `2`.
-            #[inline]
-            fn is_even(&self) -> bool { self & 1 == 0 }
-
-            /// Returns `true` if the number is not divisible by `2`.
-            #[inline]
-            fn is_odd(&self) -> bool { !self.is_even() }
-        }
-
-        #[cfg(test)]
-        mod $test_mod {
-            use Integer;
-
-            #[test]
-            fn test_div_mod_floor() {
-                assert_eq!((10 as $T).div_floor(&(3 as $T)), 3 as $T);
-                assert_eq!((10 as $T).mod_floor(&(3 as $T)), 1 as $T);
-                assert_eq!((10 as $T).div_mod_floor(&(3 as $T)), (3 as $T, 1 as $T));
-                assert_eq!((5 as $T).div_floor(&(5 as $T)), 1 as $T);
-                assert_eq!((5 as $T).mod_floor(&(5 as $T)), 0 as $T);
-                assert_eq!((5 as $T).div_mod_floor(&(5 as $T)), (1 as $T, 0 as $T));
-                assert_eq!((3 as $T).div_floor(&(7 as $T)), 0 as $T);
-                assert_eq!((3 as $T).mod_floor(&(7 as $T)), 3 as $T);
-                assert_eq!((3 as $T).div_mod_floor(&(7 as $T)), (0 as $T, 3 as $T));
-            }
-
-            #[test]
-            fn test_gcd() {
-                assert_eq!((10 as $T).gcd(&2), 2 as $T);
-                assert_eq!((10 as $T).gcd(&3), 1 as $T);
-                assert_eq!((0 as $T).gcd(&3), 3 as $T);
-                assert_eq!((3 as $T).gcd(&3), 3 as $T);
-                assert_eq!((56 as $T).gcd(&42), 14 as $T);
-            }
-
-            #[test]
-            #[allow(type_overflow)]
-            fn test_lcm() {
-                assert_eq!((1 as $T).lcm(&0), 0 as $T);
-                assert_eq!((0 as $T).lcm(&1), 0 as $T);
-                assert_eq!((1 as $T).lcm(&1), 1 as $T);
-                assert_eq!((8 as $T).lcm(&9), 72 as $T);
-                assert_eq!((11 as $T).lcm(&5), 55 as $T);
-                assert_eq!((99 as $T).lcm(&17), 1683 as $T);
-            }
-
-            #[test]
-            fn test_is_multiple_of() {
-                assert!((6 as $T).is_multiple_of(&(6 as $T)));
-                assert!((6 as $T).is_multiple_of(&(3 as $T)));
-                assert!((6 as $T).is_multiple_of(&(1 as $T)));
-            }
-
-            #[test]
-            fn test_even() {
-                assert_eq!((0 as $T).is_even(), true);
-                assert_eq!((1 as $T).is_even(), false);
-                assert_eq!((2 as $T).is_even(), true);
-                assert_eq!((3 as $T).is_even(), false);
-                assert_eq!((4 as $T).is_even(), true);
-            }
-
-            #[test]
-            fn test_odd() {
-                assert_eq!((0 as $T).is_odd(), false);
-                assert_eq!((1 as $T).is_odd(), true);
-                assert_eq!((2 as $T).is_odd(), false);
-                assert_eq!((3 as $T).is_odd(), true);
-                assert_eq!((4 as $T).is_odd(), false);
-            }
-        }
-    )
-}
-
-impl_integer_for_uint!(u8,   test_integer_u8)
-impl_integer_for_uint!(u16,  test_integer_u16)
-impl_integer_for_uint!(u32,  test_integer_u32)
-impl_integer_for_uint!(u64,  test_integer_u64)
-impl_integer_for_uint!(uint, test_integer_uint)
diff --git a/src/libnum/lib.rs b/src/libnum/lib.rs
deleted file mode 100644
index 063bb17e09a..00000000000
--- a/src/libnum/lib.rs
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Simple numerics.
-//!
-//! This crate contains arbitrary-sized integer, rational, and complex types.
-//!
-//! ## Example
-//!
-//! This example uses the BigRational type and [Newton's method][newt] to
-//! approximate a square root to arbitrary precision:
-//!
-//! ```
-//! # #![allow(deprecated)]
-//! extern crate num;
-//!
-//! use num::bigint::BigInt;
-//! use num::rational::{Ratio, BigRational};
-//!
-//! fn approx_sqrt(number: u64, iterations: uint) -> BigRational {
-//!     let start: Ratio<BigInt> = Ratio::from_integer(FromPrimitive::from_u64(number).unwrap());
-//!     let mut approx = start.clone();
-//!
-//!     for _ in range(0, iterations) {
-//!         approx = (approx + (start / approx)) /
-//!             Ratio::from_integer(FromPrimitive::from_u64(2).unwrap());
-//!     }
-//!
-//!     approx
-//! }
-//!
-//! fn main() {
-//!     println!("{}", approx_sqrt(10, 4)); // prints 4057691201/1283082416
-//! }
-//! ```
-//!
-//! [newt]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method
-
-#![allow(unknown_features)]
-#![feature(macro_rules, slicing_syntax)]
-#![feature(default_type_params)]
-
-#![crate_name = "num"]
-#![deprecated = "This is now a cargo package located at: \
-                 https://github.com/rust-lang/num"]
-#![allow(deprecated)]
-#![crate_type = "rlib"]
-#![crate_type = "dylib"]
-#![license = "MIT/ASL2"]
-#![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
-       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
-       html_root_url = "http://doc.rust-lang.org/nightly/",
-       html_playground_url = "http://play.rust-lang.org/")]
-#![allow(deprecated)] // from_str_radix
-
-extern crate rand;
-
-pub use bigint::{BigInt, BigUint};
-pub use rational::{Rational, BigRational};
-pub use complex::Complex;
-pub use integer::Integer;
-
-pub mod bigint;
-pub mod complex;
-pub mod integer;
-pub mod rational;
diff --git a/src/libnum/rational.rs b/src/libnum/rational.rs
deleted file mode 100644
index ceaf685c19a..00000000000
--- a/src/libnum/rational.rs
+++ /dev/null
@@ -1,803 +0,0 @@
-// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Rational numbers
-
-use Integer;
-
-use std::cmp;
-use std::fmt;
-use std::from_str::FromStr;
-use std::num;
-use std::num::{Zero, One, ToStrRadix, FromStrRadix};
-
-use bigint::{BigInt, BigUint, Sign, Plus, Minus};
-
-/// Represents the ratio between 2 numbers.
-#[deriving(Clone, Hash)]
-#[allow(missing_doc)]
-pub struct Ratio<T> {
-    numer: T,
-    denom: T
-}
-
-/// Alias for a `Ratio` of machine-sized integers.
-pub type Rational = Ratio<int>;
-pub type Rational32 = Ratio<i32>;
-pub type Rational64 = Ratio<i64>;
-
-/// Alias for arbitrary precision rationals.
-pub type BigRational = Ratio<BigInt>;
-
-impl<T: Clone + Integer + PartialOrd>
-    Ratio<T> {
-    /// Creates a ratio representing the integer `t`.
-    #[inline]
-    pub fn from_integer(t: T) -> Ratio<T> {
-        Ratio::new_raw(t, One::one())
-    }
-
-    /// Creates a ratio without checking for `denom == 0` or reducing.
-    #[inline]
-    pub fn new_raw(numer: T, denom: T) -> Ratio<T> {
-        Ratio { numer: numer, denom: denom }
-    }
-
-    /// Create a new Ratio. Fails if `denom == 0`.
-    #[inline]
-    pub fn new(numer: T, denom: T) -> Ratio<T> {
-        if denom == Zero::zero() {
-            fail!("denominator == 0");
-        }
-        let mut ret = Ratio::new_raw(numer, denom);
-        ret.reduce();
-        ret
-    }
-
-    /// Converts to an integer.
-    #[inline]
-    pub fn to_integer(&self) -> T {
-        self.trunc().numer
-    }
-
-    /// Gets an immutable reference to the numerator.
-    #[inline]
-    pub fn numer<'a>(&'a self) -> &'a T {
-        &self.numer
-    }
-
-    /// Gets an immutable reference to the denominator.
-    #[inline]
-    pub fn denom<'a>(&'a self) -> &'a T {
-        &self.denom
-    }
-
-    /// Returns true if the rational number is an integer (denominator is 1).
-    #[inline]
-    pub fn is_integer(&self) -> bool {
-        self.denom == One::one()
-    }
-
-    /// Put self into lowest terms, with denom > 0.
-    fn reduce(&mut self) {
-        let g : T = self.numer.gcd(&self.denom);
-
-        // FIXME(#5992): assignment operator overloads
-        // self.numer /= g;
-        self.numer = self.numer / g;
-        // FIXME(#5992): assignment operator overloads
-        // self.denom /= g;
-        self.denom = self.denom / g;
-
-        // keep denom positive!
-        if self.denom < Zero::zero() {
-            self.numer = -self.numer;
-            self.denom = -self.denom;
-        }
-    }
-
-    /// Returns a `reduce`d copy of self.
-    pub fn reduced(&self) -> Ratio<T> {
-        let mut ret = self.clone();
-        ret.reduce();
-        ret
-    }
-
-    /// Returns the reciprocal.
-    #[inline]
-    pub fn recip(&self) -> Ratio<T> {
-        Ratio::new_raw(self.denom.clone(), self.numer.clone())
-    }
-
-    /// Rounds towards minus infinity.
-    #[inline]
-    pub fn floor(&self) -> Ratio<T> {
-        if *self < Zero::zero() {
-            Ratio::from_integer((self.numer - self.denom + One::one()) / self.denom)
-        } else {
-            Ratio::from_integer(self.numer / self.denom)
-        }
-    }
-
-    /// Rounds towards plus infinity.
-    #[inline]
-    pub fn ceil(&self) -> Ratio<T> {
-        if *self < Zero::zero() {
-            Ratio::from_integer(self.numer / self.denom)
-        } else {
-            Ratio::from_integer((self.numer + self.denom - One::one()) / self.denom)
-        }
-    }
-
-    /// Rounds to the nearest integer. Rounds half-way cases away from zero.
-    #[inline]
-    pub fn round(&self) -> Ratio<T> {
-        let one: T = One::one();
-        let two: T = one + one;
-
-        // Find unsigned fractional part of rational number
-        let fractional = self.fract().abs();
-
-        // The algorithm compares the unsigned fractional part with 1/2, that
-        // is, a/b >= 1/2, or a >= b/2. For odd denominators, we use
-        // a >= (b/2)+1. This avoids overflow issues.
-        let half_or_larger = if fractional.denom().is_even() {
-            *fractional.numer() >= *fractional.denom() / two
-        } else {
-            *fractional.numer() >= (*fractional.denom() / two) + one
-        };
-
-        if half_or_larger {
-            if *self >= Zero::zero() {
-                self.trunc() + One::one()
-            } else {
-                self.trunc() - One::one()
-            }
-        } else {
-            self.trunc()
-        }
-    }
-
-    /// Rounds towards zero.
-    #[inline]
-    pub fn trunc(&self) -> Ratio<T> {
-        Ratio::from_integer(self.numer / self.denom)
-    }
-
-    /// Returns the fractional part of a number.
-    #[inline]
-    pub fn fract(&self) -> Ratio<T> {
-        Ratio::new_raw(self.numer % self.denom, self.denom.clone())
-    }
-}
-
-impl Ratio<BigInt> {
-    /// Converts a float into a rational number.
-    pub fn from_float<T: Float>(f: T) -> Option<BigRational> {
-        if !f.is_finite() {
-            return None;
-        }
-        let (mantissa, exponent, sign) = f.integer_decode();
-        let bigint_sign: Sign = if sign == 1 { Plus } else { Minus };
-        if exponent < 0 {
-            let one: BigInt = One::one();
-            let denom: BigInt = one << ((-exponent) as uint);
-            let numer: BigUint = FromPrimitive::from_u64(mantissa).unwrap();
-            Some(Ratio::new(BigInt::from_biguint(bigint_sign, numer), denom))
-        } else {
-            let mut numer: BigUint = FromPrimitive::from_u64(mantissa).unwrap();
-            numer = numer << (exponent as uint);
-            Some(Ratio::from_integer(BigInt::from_biguint(bigint_sign, numer)))
-        }
-    }
-}
-
-/* Comparisons */
-
-// comparing a/b and c/d is the same as comparing a*d and b*c, so we
-// abstract that pattern. The following macro takes a trait and either
-// a comma-separated list of "method name -> return value" or just
-// "method name" (return value is bool in that case)
-macro_rules! cmp_impl {
-    (impl $imp:ident, $($method:ident),+) => {
-        cmp_impl!(impl $imp, $($method -> bool),+)
-    };
-    // return something other than a Ratio<T>
-    (impl $imp:ident, $($method:ident -> $res:ty),*) => {
-        impl<T: Mul<T,T> + $imp> $imp for Ratio<T> {
-            $(
-                #[inline]
-                fn $method(&self, other: &Ratio<T>) -> $res {
-                    (self.numer * other.denom). $method (&(self.denom*other.numer))
-                }
-            )*
-        }
-    };
-}
-cmp_impl!(impl PartialEq, eq, ne)
-cmp_impl!(impl PartialOrd, lt -> bool, gt -> bool, le -> bool, ge -> bool,
-          partial_cmp -> Option<cmp::Ordering>)
-cmp_impl!(impl Eq, )
-cmp_impl!(impl Ord, cmp -> cmp::Ordering)
-
-/* Arithmetic */
-// a/b * c/d = (a*c)/(b*d)
-impl<T: Clone + Integer + PartialOrd>
-    Mul<Ratio<T>,Ratio<T>> for Ratio<T> {
-    #[inline]
-    fn mul(&self, rhs: &Ratio<T>) -> Ratio<T> {
-        Ratio::new(self.numer * rhs.numer, self.denom * rhs.denom)
-    }
-}
-
-// (a/b) / (c/d) = (a*d)/(b*c)
-impl<T: Clone + Integer + PartialOrd>
-    Div<Ratio<T>,Ratio<T>> for Ratio<T> {
-    #[inline]
-    fn div(&self, rhs: &Ratio<T>) -> Ratio<T> {
-        Ratio::new(self.numer * rhs.denom, self.denom * rhs.numer)
-    }
-}
-
-// Abstracts the a/b `op` c/d = (a*d `op` b*d) / (b*d) pattern
-macro_rules! arith_impl {
-    (impl $imp:ident, $method:ident) => {
-        impl<T: Clone + Integer + PartialOrd>
-            $imp<Ratio<T>,Ratio<T>> for Ratio<T> {
-            #[inline]
-            fn $method(&self, rhs: &Ratio<T>) -> Ratio<T> {
-                Ratio::new((self.numer * rhs.denom).$method(&(self.denom * rhs.numer)),
-                           self.denom * rhs.denom)
-            }
-        }
-    }
-}
-
-// a/b + c/d = (a*d + b*c)/(b*d)
-arith_impl!(impl Add, add)
-
-// a/b - c/d = (a*d - b*c)/(b*d)
-arith_impl!(impl Sub, sub)
-
-// a/b % c/d = (a*d % b*c)/(b*d)
-arith_impl!(impl Rem, rem)
-
-impl<T: Clone + Integer + PartialOrd>
-    Neg<Ratio<T>> for Ratio<T> {
-    #[inline]
-    fn neg(&self) -> Ratio<T> {
-        Ratio::new_raw(-self.numer, self.denom.clone())
-    }
-}
-
-/* Constants */
-impl<T: Clone + Integer + PartialOrd>
-    Zero for Ratio<T> {
-    #[inline]
-    fn zero() -> Ratio<T> {
-        Ratio::new_raw(Zero::zero(), One::one())
-    }
-
-    #[inline]
-    fn is_zero(&self) -> bool {
-        *self == Zero::zero()
-    }
-}
-
-impl<T: Clone + Integer + PartialOrd>
-    One for Ratio<T> {
-    #[inline]
-    fn one() -> Ratio<T> {
-        Ratio::new_raw(One::one(), One::one())
-    }
-}
-
-impl<T: Clone + Integer + PartialOrd>
-    Num for Ratio<T> {}
-
-impl<T: Clone + Integer + PartialOrd>
-    num::Signed for Ratio<T> {
-    #[inline]
-    fn abs(&self) -> Ratio<T> {
-        if self.is_negative() { -self.clone() } else { self.clone() }
-    }
-
-    #[inline]
-    fn abs_sub(&self, other: &Ratio<T>) -> Ratio<T> {
-        if *self <= *other { Zero::zero() } else { *self - *other }
-    }
-
-    #[inline]
-    fn signum(&self) -> Ratio<T> {
-        if *self > Zero::zero() {
-            num::one()
-        } else if self.is_zero() {
-            num::zero()
-        } else {
-            - num::one::<Ratio<T>>()
-        }
-    }
-
-    #[inline]
-    fn is_positive(&self) -> bool { *self > Zero::zero() }
-
-    #[inline]
-    fn is_negative(&self) -> bool { *self < Zero::zero() }
-}
-
-/* String conversions */
-impl<T: fmt::Show + Eq + One> fmt::Show for Ratio<T> {
-    /// Renders as `numer/denom`. If denom=1, renders as numer.
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if self.denom == One::one() {
-            write!(f, "{}", self.numer)
-        } else {
-            write!(f, "{}/{}", self.numer, self.denom)
-        }
-    }
-}
-
-impl<T: ToStrRadix> ToStrRadix for Ratio<T> {
-    /// Renders as `numer/denom` where the numbers are in base `radix`.
-    fn to_str_radix(&self, radix: uint) -> String {
-        format!("{}/{}",
-                self.numer.to_str_radix(radix),
-                self.denom.to_str_radix(radix))
-    }
-}
-
-impl<T: FromStr + Clone + Integer + PartialOrd>
-    FromStr for Ratio<T> {
-    /// Parses `numer/denom` or just `numer`.
-    fn from_str(s: &str) -> Option<Ratio<T>> {
-        let mut split = s.splitn(1, '/');
-
-        let num = split.next().and_then(|n| FromStr::from_str(n));
-        let den = split.next().or(Some("1")).and_then(|d| FromStr::from_str(d));
-
-        match (num, den) {
-            (Some(n), Some(d)) => Some(Ratio::new(n, d)),
-            _ => None
-        }
-    }
-}
-
-impl<T: FromStrRadix + Clone + Integer + PartialOrd>
-    FromStrRadix for Ratio<T> {
-    /// Parses `numer/denom` where the numbers are in base `radix`.
-    fn from_str_radix(s: &str, radix: uint) -> Option<Ratio<T>> {
-        let split: Vec<&str> = s.splitn(1, '/').collect();
-        if split.len() < 2 {
-            None
-        } else {
-            let a_option: Option<T> = FromStrRadix::from_str_radix(
-                *split.get(0),
-                radix);
-            a_option.and_then(|a| {
-                let b_option: Option<T> =
-                    FromStrRadix::from_str_radix(*split.get(1), radix);
-                b_option.and_then(|b| {
-                    Some(Ratio::new(a.clone(), b.clone()))
-                })
-            })
-        }
-    }
-}
-
-#[cfg(test)]
-mod test {
-
-    use super::{Ratio, Rational, BigRational};
-    use std::num::{Zero, One, FromStrRadix, FromPrimitive, ToStrRadix};
-    use std::from_str::FromStr;
-    use std::hash::hash;
-    use std::num;
-    use std::i32;
-
-    pub static _0 : Rational = Ratio { numer: 0, denom: 1};
-    pub static _1 : Rational = Ratio { numer: 1, denom: 1};
-    pub static _2: Rational = Ratio { numer: 2, denom: 1};
-    pub static _1_2: Rational = Ratio { numer: 1, denom: 2};
-    pub static _3_2: Rational = Ratio { numer: 3, denom: 2};
-    #[allow(non_uppercase_statics)]
-    pub static _neg1_2: Rational = Ratio { numer: -1, denom: 2};
-    pub static _1_3: Rational = Ratio { numer: 1, denom: 3};
-    #[allow(non_uppercase_statics)]
-    pub static _neg1_3: Rational = Ratio { numer: -1, denom: 3};
-    pub static _2_3: Rational = Ratio { numer: 2, denom: 3};
-    #[allow(non_uppercase_statics)]
-    pub static _neg2_3: Rational = Ratio { numer: -2, denom: 3};
-
-    pub fn to_big(n: Rational) -> BigRational {
-        Ratio::new(
-            FromPrimitive::from_int(n.numer).unwrap(),
-            FromPrimitive::from_int(n.denom).unwrap()
-        )
-    }
-
-    #[test]
-    fn test_test_constants() {
-        // check our constants are what Ratio::new etc. would make.
-        assert_eq!(_0, Zero::zero());
-        assert_eq!(_1, One::one());
-        assert_eq!(_2, Ratio::from_integer(2i));
-        assert_eq!(_1_2, Ratio::new(1i,2i));
-        assert_eq!(_3_2, Ratio::new(3i,2i));
-        assert_eq!(_neg1_2, Ratio::new(-1i,2i));
-    }
-
-    #[test]
-    fn test_new_reduce() {
-        let one22 = Ratio::new(2i,2);
-
-        assert_eq!(one22, One::one());
-    }
-    #[test]
-    #[should_fail]
-    fn test_new_zero() {
-        let _a = Ratio::new(1i,0);
-    }
-
-
-    #[test]
-    fn test_cmp() {
-        assert!(_0 == _0 && _1 == _1);
-        assert!(_0 != _1 && _1 != _0);
-        assert!(_0 < _1 && !(_1 < _0));
-        assert!(_1 > _0 && !(_0 > _1));
-
-        assert!(_0 <= _0 && _1 <= _1);
-        assert!(_0 <= _1 && !(_1 <= _0));
-
-        assert!(_0 >= _0 && _1 >= _1);
-        assert!(_1 >= _0 && !(_0 >= _1));
-    }
-
-
-    #[test]
-    fn test_to_integer() {
-        assert_eq!(_0.to_integer(), 0);
-        assert_eq!(_1.to_integer(), 1);
-        assert_eq!(_2.to_integer(), 2);
-        assert_eq!(_1_2.to_integer(), 0);
-        assert_eq!(_3_2.to_integer(), 1);
-        assert_eq!(_neg1_2.to_integer(), 0);
-    }
-
-
-    #[test]
-    fn test_numer() {
-        assert_eq!(_0.numer(), &0);
-        assert_eq!(_1.numer(), &1);
-        assert_eq!(_2.numer(), &2);
-        assert_eq!(_1_2.numer(), &1);
-        assert_eq!(_3_2.numer(), &3);
-        assert_eq!(_neg1_2.numer(), &(-1));
-    }
-    #[test]
-    fn test_denom() {
-        assert_eq!(_0.denom(), &1);
-        assert_eq!(_1.denom(), &1);
-        assert_eq!(_2.denom(), &1);
-        assert_eq!(_1_2.denom(), &2);
-        assert_eq!(_3_2.denom(), &2);
-        assert_eq!(_neg1_2.denom(), &2);
-    }
-
-
-    #[test]
-    fn test_is_integer() {
-        assert!(_0.is_integer());
-        assert!(_1.is_integer());
-        assert!(_2.is_integer());
-        assert!(!_1_2.is_integer());
-        assert!(!_3_2.is_integer());
-        assert!(!_neg1_2.is_integer());
-    }
-
-    #[test]
-    fn test_show() {
-        assert_eq!(format!("{}", _2), "2".to_string());
-        assert_eq!(format!("{}", _1_2), "1/2".to_string());
-        assert_eq!(format!("{}", _0), "0".to_string());
-        assert_eq!(format!("{}", Ratio::from_integer(-2i)), "-2".to_string());
-    }
-
-    mod arith {
-        use super::{_0, _1, _2, _1_2, _3_2, _neg1_2, to_big};
-        use super::super::{Ratio, Rational};
-
-        #[test]
-        fn test_add() {
-            fn test(a: Rational, b: Rational, c: Rational) {
-                assert_eq!(a + b, c);
-                assert_eq!(to_big(a) + to_big(b), to_big(c));
-            }
-
-            test(_1, _1_2, _3_2);
-            test(_1, _1, _2);
-            test(_1_2, _3_2, _2);
-            test(_1_2, _neg1_2, _0);
-        }
-
-        #[test]
-        fn test_sub() {
-            fn test(a: Rational, b: Rational, c: Rational) {
-                assert_eq!(a - b, c);
-                assert_eq!(to_big(a) - to_big(b), to_big(c))
-            }
-
-            test(_1, _1_2, _1_2);
-            test(_3_2, _1_2, _1);
-            test(_1, _neg1_2, _3_2);
-        }
-
-        #[test]
-        fn test_mul() {
-            fn test(a: Rational, b: Rational, c: Rational) {
-                assert_eq!(a * b, c);
-                assert_eq!(to_big(a) * to_big(b), to_big(c))
-            }
-
-            test(_1, _1_2, _1_2);
-            test(_1_2, _3_2, Ratio::new(3i,4i));
-            test(_1_2, _neg1_2, Ratio::new(-1i, 4i));
-        }
-
-        #[test]
-        fn test_div() {
-            fn test(a: Rational, b: Rational, c: Rational) {
-                assert_eq!(a / b, c);
-                assert_eq!(to_big(a) / to_big(b), to_big(c))
-            }
-
-            test(_1, _1_2, _2);
-            test(_3_2, _1_2, _1 + _2);
-            test(_1, _neg1_2, _neg1_2 + _neg1_2 + _neg1_2 + _neg1_2);
-        }
-
-        #[test]
-        fn test_rem() {
-            fn test(a: Rational, b: Rational, c: Rational) {
-                assert_eq!(a % b, c);
-                assert_eq!(to_big(a) % to_big(b), to_big(c))
-            }
-
-            test(_3_2, _1, _1_2);
-            test(_2, _neg1_2, _0);
-            test(_1_2, _2,  _1_2);
-        }
-
-        #[test]
-        fn test_neg() {
-            fn test(a: Rational, b: Rational) {
-                assert_eq!(-a, b);
-                assert_eq!(-to_big(a), to_big(b))
-            }
-
-            test(_0, _0);
-            test(_1_2, _neg1_2);
-            test(-_1, _1);
-        }
-        #[test]
-        fn test_zero() {
-            assert_eq!(_0 + _0, _0);
-            assert_eq!(_0 * _0, _0);
-            assert_eq!(_0 * _1, _0);
-            assert_eq!(_0 / _neg1_2, _0);
-            assert_eq!(_0 - _0, _0);
-        }
-        #[test]
-        #[should_fail]
-        fn test_div_0() {
-            let _a =  _1 / _0;
-        }
-    }
-
-    #[test]
-    fn test_round() {
-        assert_eq!(_1_3.ceil(), _1);
-        assert_eq!(_1_3.floor(), _0);
-        assert_eq!(_1_3.round(), _0);
-        assert_eq!(_1_3.trunc(), _0);
-
-        assert_eq!(_neg1_3.ceil(), _0);
-        assert_eq!(_neg1_3.floor(), -_1);
-        assert_eq!(_neg1_3.round(), _0);
-        assert_eq!(_neg1_3.trunc(), _0);
-
-        assert_eq!(_2_3.ceil(), _1);
-        assert_eq!(_2_3.floor(), _0);
-        assert_eq!(_2_3.round(), _1);
-        assert_eq!(_2_3.trunc(), _0);
-
-        assert_eq!(_neg2_3.ceil(), _0);
-        assert_eq!(_neg2_3.floor(), -_1);
-        assert_eq!(_neg2_3.round(), -_1);
-        assert_eq!(_neg2_3.trunc(), _0);
-
-        assert_eq!(_1_2.ceil(), _1);
-        assert_eq!(_1_2.floor(), _0);
-        assert_eq!(_1_2.round(), _1);
-        assert_eq!(_1_2.trunc(), _0);
-
-        assert_eq!(_neg1_2.ceil(), _0);
-        assert_eq!(_neg1_2.floor(), -_1);
-        assert_eq!(_neg1_2.round(), -_1);
-        assert_eq!(_neg1_2.trunc(), _0);
-
-        assert_eq!(_1.ceil(), _1);
-        assert_eq!(_1.floor(), _1);
-        assert_eq!(_1.round(), _1);
-        assert_eq!(_1.trunc(), _1);
-
-        // Overflow checks
-
-        let _neg1 = Ratio::from_integer(-1);
-        let _large_rat1 = Ratio::new(i32::MAX, i32::MAX-1);
-        let _large_rat2 = Ratio::new(i32::MAX-1, i32::MAX);
-        let _large_rat3 = Ratio::new(i32::MIN+2, i32::MIN+1);
-        let _large_rat4 = Ratio::new(i32::MIN+1, i32::MIN+2);
-        let _large_rat5 = Ratio::new(i32::MIN+2, i32::MAX);
-        let _large_rat6 = Ratio::new(i32::MAX, i32::MIN+2);
-        let _large_rat7 = Ratio::new(1, i32::MIN+1);
-        let _large_rat8 = Ratio::new(1, i32::MAX);
-
-        assert_eq!(_large_rat1.round(), One::one());
-        assert_eq!(_large_rat2.round(), One::one());
-        assert_eq!(_large_rat3.round(), One::one());
-        assert_eq!(_large_rat4.round(), One::one());
-        assert_eq!(_large_rat5.round(), _neg1);
-        assert_eq!(_large_rat6.round(), _neg1);
-        assert_eq!(_large_rat7.round(), Zero::zero());
-        assert_eq!(_large_rat8.round(), Zero::zero());
-    }
-
-    #[test]
-    fn test_fract() {
-        assert_eq!(_1.fract(), _0);
-        assert_eq!(_neg1_2.fract(), _neg1_2);
-        assert_eq!(_1_2.fract(), _1_2);
-        assert_eq!(_3_2.fract(), _1_2);
-    }
-
-    #[test]
-    fn test_recip() {
-        assert_eq!(_1 * _1.recip(), _1);
-        assert_eq!(_2 * _2.recip(), _1);
-        assert_eq!(_1_2 * _1_2.recip(), _1);
-        assert_eq!(_3_2 * _3_2.recip(), _1);
-        assert_eq!(_neg1_2 * _neg1_2.recip(), _1);
-    }
-
-    #[test]
-    fn test_to_from_str() {
-        fn test(r: Rational, s: String) {
-            assert_eq!(FromStr::from_str(s.as_slice()), Some(r));
-            assert_eq!(r.to_string(), s);
-        }
-        test(_1, "1".to_string());
-        test(_0, "0".to_string());
-        test(_1_2, "1/2".to_string());
-        test(_3_2, "3/2".to_string());
-        test(_2, "2".to_string());
-        test(_neg1_2, "-1/2".to_string());
-    }
-    #[test]
-    fn test_from_str_fail() {
-        fn test(s: &str) {
-            let rational: Option<Rational> = FromStr::from_str(s);
-            assert_eq!(rational, None);
-        }
-
-        let xs = ["0 /1", "abc", "", "1/", "--1/2","3/2/1"];
-        for &s in xs.iter() {
-            test(s);
-        }
-    }
-
-    #[test]
-    fn test_to_from_str_radix() {
-        fn test(r: Rational, s: String, n: uint) {
-            assert_eq!(FromStrRadix::from_str_radix(s.as_slice(), n),
-                       Some(r));
-            assert_eq!(r.to_str_radix(n).to_string(), s);
-        }
-        fn test3(r: Rational, s: String) { test(r, s, 3) }
-        fn test16(r: Rational, s: String) { test(r, s, 16) }
-
-        test3(_1, "1/1".to_string());
-        test3(_0, "0/1".to_string());
-        test3(_1_2, "1/2".to_string());
-        test3(_3_2, "10/2".to_string());
-        test3(_2, "2/1".to_string());
-        test3(_neg1_2, "-1/2".to_string());
-        test3(_neg1_2 / _2, "-1/11".to_string());
-
-        test16(_1, "1/1".to_string());
-        test16(_0, "0/1".to_string());
-        test16(_1_2, "1/2".to_string());
-        test16(_3_2, "3/2".to_string());
-        test16(_2, "2/1".to_string());
-        test16(_neg1_2, "-1/2".to_string());
-        test16(_neg1_2 / _2, "-1/4".to_string());
-        test16(Ratio::new(13i,15i), "d/f".to_string());
-        test16(_1_2*_1_2*_1_2*_1_2, "1/10".to_string());
-    }
-
-    #[test]
-    fn test_from_str_radix_fail() {
-        fn test(s: &str) {
-            let radix: Option<Rational> = FromStrRadix::from_str_radix(s, 3);
-            assert_eq!(radix, None);
-        }
-
-        let xs = ["0 /1", "abc", "", "1/", "--1/2","3/2/1", "3/2"];
-        for &s in xs.iter() {
-            test(s);
-        }
-    }
-
-    #[test]
-    fn test_from_float() {
-        fn test<T: Float>(given: T, (numer, denom): (&str, &str)) {
-            let ratio: BigRational = Ratio::from_float(given).unwrap();
-            assert_eq!(ratio, Ratio::new(
-                FromStr::from_str(numer).unwrap(),
-                FromStr::from_str(denom).unwrap()));
-        }
-
-        // f32
-        test(3.14159265359f32, ("13176795", "4194304"));
-        test(2f32.powf(100.), ("1267650600228229401496703205376", "1"));
-        test(-2f32.powf(100.), ("-1267650600228229401496703205376", "1"));
-        test(1.0 / 2f32.powf(100.), ("1", "1267650600228229401496703205376"));
-        test(684729.48391f32, ("1369459", "2"));
-        test(-8573.5918555f32, ("-4389679", "512"));
-
-        // f64
-        test(3.14159265359f64, ("3537118876014453", "1125899906842624"));
-        test(2f64.powf(100.), ("1267650600228229401496703205376", "1"));
-        test(-2f64.powf(100.), ("-1267650600228229401496703205376", "1"));
-        test(684729.48391f64, ("367611342500051", "536870912"));
-        test(-8573.5918555f64, ("-4713381968463931", "549755813888"));
-        test(1.0 / 2f64.powf(100.), ("1", "1267650600228229401496703205376"));
-    }
-
-    #[test]
-    fn test_from_float_fail() {
-        use std::{f32, f64};
-
-        assert_eq!(Ratio::from_float(f32::NAN), None);
-        assert_eq!(Ratio::from_float(f32::INFINITY), None);
-        assert_eq!(Ratio::from_float(f32::NEG_INFINITY), None);
-        assert_eq!(Ratio::from_float(f64::NAN), None);
-        assert_eq!(Ratio::from_float(f64::INFINITY), None);
-        assert_eq!(Ratio::from_float(f64::NEG_INFINITY), None);
-    }
-
-    #[test]
-    fn test_signed() {
-        assert_eq!(_neg1_2.abs(), _1_2);
-        assert_eq!(_3_2.abs_sub(&_1_2), _1);
-        assert_eq!(_1_2.abs_sub(&_3_2), Zero::zero());
-        assert_eq!(_1_2.signum(), One::one());
-        assert_eq!(_neg1_2.signum(), - num::one::<Ratio<int>>());
-        assert!(_neg1_2.is_negative());
-        assert!(! _neg1_2.is_positive());
-        assert!(! _1_2.is_negative());
-    }
-
-    #[test]
-    fn test_hash() {
-        assert!(hash(&_0) != hash(&_1));
-        assert!(hash(&_0) != hash(&_3_2));
-    }
-}