Use `#[prelude_import]` in `libcore`.

46 files changed, 30 insertions, 183 deletions

diff --git a/src/libcore/any.rs b/src/libcore/any.rs
index a452be2565b..4f486ad7cb8 100644
--- a/src/libcore/any.rs
+++ b/src/libcore/any.rs
@@ -72,12 +72,10 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use fmt;
-use marker::Send;
 use mem::transmute;
-use option::Option::{self, Some, None};
 use raw::TraitObject;
 use intrinsics;
-use marker::{Reflect, Sized};
+use marker::Reflect;
 
 ///////////////////////////////////////////////////////////////////////////////
 // Any trait
diff --git a/src/libcore/array.rs b/src/libcore/array.rs
index 45fc5ff8009..9866a39619a 100644
--- a/src/libcore/array.rs
+++ b/src/libcore/array.rs
@@ -20,16 +20,11 @@
             issue = "27778")]
 
 use borrow::{Borrow, BorrowMut};
-use clone::Clone;
-use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
-use convert::{AsRef, AsMut};
-use default::Default;
+use cmp::Ordering;
 use fmt;
 use hash::{Hash, self};
-use iter::IntoIterator;
-use marker::{Copy, Sized, Unsize};
-use option::Option;
-use slice::{Iter, IterMut, SliceExt};
+use marker::Unsize;
+use slice::{Iter, IterMut};
 
 /// Utility trait implemented only on arrays of fixed size
 ///
diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs
index 79330d3a61e..3d223465c88 100644
--- a/src/libcore/borrow.rs
+++ b/src/libcore/borrow.rs
@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A trait for borrowing data.
 ///
 /// In general, there may be several ways to "borrow" a piece of data.  The
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 2af48ef2fab..ec35198b685 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -144,17 +144,10 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
-use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
-use convert::From;
-use default::Default;
+use cmp::Ordering;
 use fmt::{self, Debug, Display};
-use marker::{Copy, PhantomData, Send, Sync, Sized, Unsize};
-use ops::{Deref, DerefMut, Drop, FnOnce, CoerceUnsized};
-use option::Option;
-use option::Option::{None, Some};
-use result::Result;
-use result::Result::{Ok, Err};
+use marker::{PhantomData, Unsize};
+use ops::{Deref, DerefMut, CoerceUnsized};
 
 /// A mutable memory location that admits only `Copy` data.
 ///
diff --git a/src/libcore/char.rs b/src/libcore/char.rs
index 98b7632a220..64cb6dc2314 100644
--- a/src/libcore/char.rs
+++ b/src/libcore/char.rs
@@ -15,8 +15,6 @@
 #![allow(non_snake_case)]
 #![stable(feature = "core_char", since = "1.2.0")]
 
-use prelude::v1::*;
-
 use char_private::is_printable;
 use iter::FusedIterator;
 use mem::transmute;
diff --git a/src/libcore/char_private.rs b/src/libcore/char_private.rs
index 1d8f95cd4b8..708e7cc15e7 100644
--- a/src/libcore/char_private.rs
+++ b/src/libcore/char_private.rs
@@ -11,8 +11,6 @@
 // NOTE: The following code was generated by "src/etc/char_private.py",
 //       do not edit directly!
 
-use slice::SliceExt;
-
 fn check(x: u16, singletons: &[u16], normal: &[u16]) -> bool {
     for &s in singletons {
         if x == s {
diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index e8cd36f3cd7..748bb62a1f3 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -44,8 +44,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A common trait for the ability to explicitly duplicate an object.
 ///
 /// Differs from `Copy` in that `Copy` is implicit and extremely inexpensive, while
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 9bba6cd38e5..907dd1508d8 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -34,9 +34,6 @@
 
 use self::Ordering::*;
 
-use marker::Sized;
-use option::Option::{self, Some};
-
 /// Trait for equality comparisons which are [partial equivalence
 /// relations](http://en.wikipedia.org/wiki/Partial_equivalence_relation).
 ///
@@ -571,11 +568,7 @@ pub fn max<T: Ord>(v1: T, v2: T) -> T {
 
 // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types
 mod impls {
-    use cmp::{PartialOrd, Ord, PartialEq, Eq, Ordering};
-    use cmp::Ordering::{Less, Greater, Equal};
-    use marker::Sized;
-    use option::Option;
-    use option::Option::{Some, None};
+    use cmp::Ordering::{self, Less, Greater, Equal};
 
     macro_rules! partial_eq_impl {
         ($($t:ty)*) => ($(
diff --git a/src/libcore/convert.rs b/src/libcore/convert.rs
index e68f973d8d9..8e7e2abfc1e 100644
--- a/src/libcore/convert.rs
+++ b/src/libcore/convert.rs
@@ -40,9 +40,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-use result::Result;
-
 /// A cheap, reference-to-reference conversion.
 ///
 /// `AsRef` is very similar to, but different than, `Borrow`. See
diff --git a/src/libcore/default.rs b/src/libcore/default.rs
index a0dd38c983b..85e4b2a0067 100644
--- a/src/libcore/default.rs
+++ b/src/libcore/default.rs
@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A trait for giving a type a useful default value.
 ///
 /// Sometimes, you want to fall back to some kind of default value, and
diff --git a/src/libcore/fmt/builders.rs b/src/libcore/fmt/builders.rs
index 6cac80ab624..102e3c0bd7b 100644
--- a/src/libcore/fmt/builders.rs
+++ b/src/libcore/fmt/builders.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
 use fmt::{self, FlagV1};
 
 struct PadAdapter<'a, 'b: 'a> {
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 7688da971eb..66ef92928eb 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use cell::{UnsafeCell, Cell, RefCell, Ref, RefMut, BorrowState};
 use marker::PhantomData;
 use mem;
@@ -905,8 +903,6 @@ impl<'a> Formatter<'a> {
                         prefix: &str,
                         buf: &str)
                         -> Result {
-        use char::CharExt;
-
         let mut width = buf.len();
 
         let mut sign = None;
@@ -1020,7 +1016,6 @@ impl<'a> Formatter<'a> {
                        f: F) -> Result
         where F: FnOnce(&mut Formatter) -> Result,
     {
-        use char::CharExt;
         let align = match self.align {
             rt::v1::Alignment::Unknown => default,
             _ => self.align
diff --git a/src/libcore/fmt/num.rs b/src/libcore/fmt/num.rs
index d55e0317a94..0145897d8f6 100644
--- a/src/libcore/fmt/num.rs
+++ b/src/libcore/fmt/num.rs
@@ -14,8 +14,6 @@
 
 // FIXME: #6220 Implement floating point formatting
 
-use prelude::v1::*;
-
 use fmt;
 use num::Zero;
 use ops::{Div, Rem, Sub};
diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index 27fdbd38301..081f0c14ec3 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -71,8 +71,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use fmt;
 use marker;
 use mem;
@@ -288,8 +286,6 @@ impl<H> Default for BuildHasherDefault<H> {
 //////////////////////////////////////////////////////////////////////////////
 
 mod impls {
-    use prelude::v1::*;
-
     use mem;
     use slice;
     use super::*;
diff --git a/src/libcore/hash/sip.rs b/src/libcore/hash/sip.rs
index 4a806a3c986..bd6cae92b05 100644
--- a/src/libcore/hash/sip.rs
+++ b/src/libcore/hash/sip.rs
@@ -10,8 +10,6 @@
 
 //! An implementation of SipHash.
 
-use prelude::v1::*;
-
 use marker::PhantomData;
 use ptr;
 
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index c645608dda7..b70bf43ac35 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -46,8 +46,6 @@
             issue = "0")]
 #![allow(missing_docs)]
 
-use marker::Sized;
-
 extern "rust-intrinsic" {
 
     // NB: These intrinsics take raw pointers because they mutate aliased
diff --git a/src/libcore/iter/iterator.rs b/src/libcore/iter/iterator.rs
index 6b01ccaceea..ea97c87efbb 100644
--- a/src/libcore/iter/iterator.rs
+++ b/src/libcore/iter/iterator.rs
@@ -8,19 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use cmp::{Ord, PartialOrd, PartialEq, Ordering};
-use default::Default;
-use ops::FnMut;
-use option::Option::{self, Some, None};
-use marker::Sized;
+use cmp::Ordering;
 
 use super::{Chain, Cycle, Cloned, Enumerate, Filter, FilterMap, FlatMap, Fuse};
 use super::{Inspect, Map, Peekable, Scan, Skip, SkipWhile, Take, TakeWhile, Rev};
 use super::{Zip, Sum, Product};
-use super::ChainState;
-use super::{DoubleEndedIterator, ExactSizeIterator, Extend, FromIterator};
-use super::{IntoIterator, ZipImpl};
+use super::{ChainState, FromIterator, ZipImpl};
 
 fn _assert_is_object_safe(_: &Iterator<Item=()>) {}
 
diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs
index cfe117c0b1d..b1d3ab1d1fe 100644
--- a/src/libcore/iter/mod.rs
+++ b/src/libcore/iter/mod.rs
@@ -299,13 +299,9 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use cmp;
-use default::Default;
 use fmt;
 use iter_private::TrustedRandomAccess;
-use ops::FnMut;
-use option::Option::{self, Some, None};
 use usize;
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libcore/iter/range.rs b/src/libcore/iter/range.rs
index 48816bf66bb..8408e5d88b4 100644
--- a/src/libcore/iter/range.rs
+++ b/src/libcore/iter/range.rs
@@ -8,15 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use cmp::PartialOrd;
 use mem;
 use ops::{self, Add, Sub};
-use option::Option::{self, Some, None};
-use marker::Sized;
 use usize;
 
-use super::{DoubleEndedIterator, ExactSizeIterator, Iterator, FusedIterator};
+use super::FusedIterator;
 
 /// Objects that can be stepped over in both directions.
 ///
diff --git a/src/libcore/iter/sources.rs b/src/libcore/iter/sources.rs
index a2a019a07dc..da346eaf1db 100644
--- a/src/libcore/iter/sources.rs
+++ b/src/libcore/iter/sources.rs
@@ -8,14 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use default::Default;
 use fmt;
 use marker;
-use option::Option::{self, Some, None};
 use usize;
 
-use super::{DoubleEndedIterator, IntoIterator, Iterator, ExactSizeIterator, FusedIterator};
+use super::FusedIterator;
 
 /// An iterator that repeats an element endlessly.
 ///
diff --git a/src/libcore/iter/traits.rs b/src/libcore/iter/traits.rs
index 6f80a024681..59e23c4d960 100644
--- a/src/libcore/iter/traits.rs
+++ b/src/libcore/iter/traits.rs
@@ -8,11 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use option::Option::{self, Some};
-use marker::Sized;
-
-use super::Iterator;
-
 /// Conversion from an `Iterator`.
 ///
 /// By implementing `FromIterator` for a type, you define how it will be
diff --git a/src/libcore/iter_private.rs b/src/libcore/iter_private.rs
index effe43cc67c..83eeef31ab0 100644
--- a/src/libcore/iter_private.rs
+++ b/src/libcore/iter_private.rs
@@ -9,8 +9,6 @@
 // except according to those terms.
 
 
-use iter::ExactSizeIterator;
-
 /// An iterator whose items are random accessible efficiently
 ///
 /// # Safety
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index fbeddf26b93..1ae4cf8e5ef 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -91,6 +91,11 @@
 #![feature(unboxed_closures)]
 #![feature(question_mark)]
 #![feature(never_type)]
+#![feature(prelude_import)]
+
+#[prelude_import]
+#[allow(unused)]
+use prelude::v1::*;
 
 #[macro_use]
 mod macros;
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 894982abaa9..0a46813df7e 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -16,10 +16,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use cmp;
-use default::Default;
-use option::Option;
 use hash::Hash;
 use hash::Hasher;
 
@@ -414,8 +411,6 @@ pub struct PhantomData<T:?Sized>;
 impls! { PhantomData }
 
 mod impls {
-    use super::{Send, Sync, Sized};
-
     #[stable(feature = "rust1", since = "1.0.0")]
     unsafe impl<'a, T: Sync + ?Sized> Send for &'a T {}
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index 5c2179ccf33..3526e555b0e 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -15,7 +15,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
 use intrinsics;
 use ptr;
 
diff --git a/src/libcore/nonzero.rs b/src/libcore/nonzero.rs
index 92bbc4efb7c..47afaf77353 100644
--- a/src/libcore/nonzero.rs
+++ b/src/libcore/nonzero.rs
@@ -13,7 +13,6 @@
             reason = "needs an RFC to flesh out the design",
             issue = "27730")]
 
-use marker::Sized;
 use ops::{CoerceUnsized, Deref};
 
 /// Unsafe trait to indicate what types are usable with the NonZero struct
diff --git a/src/libcore/num/bignum.rs b/src/libcore/num/bignum.rs
index a881b539ced..bc503ba3e46 100644
--- a/src/libcore/num/bignum.rs
+++ b/src/libcore/num/bignum.rs
@@ -27,8 +27,6 @@
             issue = "0")]
 #![macro_use]
 
-use prelude::v1::*;
-
 use mem;
 use intrinsics;
 
@@ -494,6 +492,5 @@ define_bignum!(Big32x40: type=Digit32, n=40);
 // this one is used for testing only.
 #[doc(hidden)]
 pub mod tests {
-    use prelude::v1::*;
     define_bignum!(Big8x3: type=u8, n=3);
 }
diff --git a/src/libcore/num/dec2flt/algorithm.rs b/src/libcore/num/dec2flt/algorithm.rs
index 4761727cec0..604bc7c10de 100644
--- a/src/libcore/num/dec2flt/algorithm.rs
+++ b/src/libcore/num/dec2flt/algorithm.rs
@@ -10,7 +10,6 @@
 
 //! The various algorithms from the paper.
 
-use prelude::v1::*;
 use cmp::min;
 use cmp::Ordering::{Less, Equal, Greater};
 use num::diy_float::Fp;
@@ -47,7 +46,6 @@ mod fpu_precision {
 #[cfg(all(target_arch="x86", not(target_feature="sse2")))]
 mod fpu_precision {
     use mem::size_of;
-    use ops::Drop;
 
     /// A structure used to preserve the original value of the FPU control word, so that it can be
     /// restored when the structure is dropped.
diff --git a/src/libcore/num/dec2flt/mod.rs b/src/libcore/num/dec2flt/mod.rs
index ff2d85307b1..cd40e399ab9 100644
--- a/src/libcore/num/dec2flt/mod.rs
+++ b/src/libcore/num/dec2flt/mod.rs
@@ -92,7 +92,6 @@
             reason = "internal routines only exposed for testing",
             issue = "0")]
 
-use prelude::v1::*;
 use fmt;
 use str::FromStr;
 
diff --git a/src/libcore/num/dec2flt/num.rs b/src/libcore/num/dec2flt/num.rs
index 81e7856633b..34b41fa9dec 100644
--- a/src/libcore/num/dec2flt/num.rs
+++ b/src/libcore/num/dec2flt/num.rs
@@ -12,7 +12,6 @@
 
 // FIXME This module's name is a bit unfortunate, since other modules also import `core::num`.
 
-use prelude::v1::*;
 use cmp::Ordering::{self, Less, Equal, Greater};
 
 pub use num::bignum::Big32x40 as Big;
diff --git a/src/libcore/num/dec2flt/parse.rs b/src/libcore/num/dec2flt/parse.rs
index fce1c250a02..d20986faa0f 100644
--- a/src/libcore/num/dec2flt/parse.rs
+++ b/src/libcore/num/dec2flt/parse.rs
@@ -20,7 +20,6 @@
 //! modules rely on to not panic (or overflow) in turn.
 //! To make matters worse, all that happens in a single pass over the input.
 //! So, be careful when modifying anything, and double-check with the other modules.
-use prelude::v1::*;
 use super::num;
 use self::ParseResult::{Valid, ShortcutToInf, ShortcutToZero, Invalid};
 
diff --git a/src/libcore/num/dec2flt/rawfp.rs b/src/libcore/num/dec2flt/rawfp.rs
index 68e4dc4b359..e3b58b6cc7c 100644
--- a/src/libcore/num/dec2flt/rawfp.rs
+++ b/src/libcore/num/dec2flt/rawfp.rs
@@ -27,7 +27,6 @@
 //! Many functions in this module only handle normal numbers. The dec2flt routines conservatively
 //! take the universally-correct slow path (Algorithm M) for very small and very large numbers.
 //! That algorithm needs only next_float() which does handle subnormals and zeros.
-use prelude::v1::*;
 use u32;
 use cmp::Ordering::{Less, Equal, Greater};
 use ops::{Mul, Div, Neg};
diff --git a/src/libcore/num/flt2dec/decoder.rs b/src/libcore/num/flt2dec/decoder.rs
index 5420e7bdd2a..276667e44aa 100644
--- a/src/libcore/num/flt2dec/decoder.rs
+++ b/src/libcore/num/flt2dec/decoder.rs
@@ -10,8 +10,6 @@
 
 //! Decodes a floating-point value into individual parts and error ranges.
 
-use prelude::v1::*;
-
 use {f32, f64};
 use num::FpCategory;
 use num::dec2flt::rawfp::RawFloat;
diff --git a/src/libcore/num/flt2dec/mod.rs b/src/libcore/num/flt2dec/mod.rs
index b549f334242..f6c03a59f81 100644
--- a/src/libcore/num/flt2dec/mod.rs
+++ b/src/libcore/num/flt2dec/mod.rs
@@ -130,7 +130,6 @@ functions.
             reason = "internal routines only exposed for testing",
             issue = "0")]
 
-use prelude::v1::*;
 use i16;
 pub use self::decoder::{decode, DecodableFloat, FullDecoded, Decoded};
 
diff --git a/src/libcore/num/flt2dec/strategy/dragon.rs b/src/libcore/num/flt2dec/strategy/dragon.rs
index 2d68c3a6d02..6aa4f297e75 100644
--- a/src/libcore/num/flt2dec/strategy/dragon.rs
+++ b/src/libcore/num/flt2dec/strategy/dragon.rs
@@ -15,8 +15,6 @@ Almost direct (but slightly optimized) Rust translation of Figure 3 of [1].
     quickly and accurately. SIGPLAN Not. 31, 5 (May. 1996), 108-116.
 */
 
-use prelude::v1::*;
-
 use cmp::Ordering;
 
 use num::flt2dec::{Decoded, MAX_SIG_DIGITS, round_up};
diff --git a/src/libcore/num/flt2dec/strategy/grisu.rs b/src/libcore/num/flt2dec/strategy/grisu.rs
index 13e01d9a7f7..cf70a1978f5 100644
--- a/src/libcore/num/flt2dec/strategy/grisu.rs
+++ b/src/libcore/num/flt2dec/strategy/grisu.rs
@@ -16,8 +16,6 @@ Rust adaptation of Grisu3 algorithm described in [1]. It uses about
     accurately with integers. SIGPLAN Not. 45, 6 (June 2010), 233-243.
 */
 
-use prelude::v1::*;
-
 use num::diy_float::Fp;
 use num::flt2dec::{Decoded, MAX_SIG_DIGITS, round_up};
 
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 4636811aa46..29ee29eb3eb 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -12,17 +12,11 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use char::CharExt;
-use cmp::PartialOrd;
-use convert::{From, TryFrom};
+use convert::TryFrom;
 use fmt;
 use intrinsics;
-use marker::{Copy, Sized};
 use mem::size_of;
-use option::Option::{self, Some, None};
-use result::Result::{self, Ok, Err};
-use str::{FromStr, StrExt};
-use slice::SliceExt;
+use str::FromStr;
 
 /// Provides intentionally-wrapped arithmetic on `T`.
 ///
diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs
index c9124249bf5..fd1a7c0827f 100644
--- a/src/libcore/ops.rs
+++ b/src/libcore/ops.rs
@@ -71,10 +71,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use cmp::PartialOrd;
 use fmt;
-use marker::{Sized, Unsize};
-use result::Result::{self, Ok, Err};
+use marker::Unsize;
 
 /// The `Drop` trait is used to run some code when a value goes out of scope.
 /// This is sometimes called a 'destructor'.
@@ -2184,9 +2182,6 @@ pub trait FnOnce<Args> {
 }
 
 mod impls {
-    use marker::Sized;
-    use super::{Fn, FnMut, FnOnce};
-
     #[stable(feature = "rust1", since = "1.0.0")]
     impl<'a,A,F:?Sized> Fn<A> for &'a F
         where F : Fn<A>
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 51bbad085fb..cf52849e019 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -139,17 +139,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use self::Option::*;
-
-use clone::Clone;
-use convert::From;
-use default::Default;
-use iter::{Iterator, FromIterator, IntoIterator, ExactSizeIterator, DoubleEndedIterator};
-use iter::FusedIterator;
+use iter::{FromIterator, FusedIterator};
 use mem;
-use ops::FnOnce;
-use result::Result::{Ok, Err};
-use result::Result;
 
 // Note that this is not a lang item per se, but it has a hidden dependency on
 // `Iterator`, which is one. The compiler assumes that the `next` method of
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 8cb485872b3..f23b407bda4 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -16,17 +16,14 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use intrinsics;
 use ops::{CoerceUnsized, Deref};
 use fmt;
 use hash;
-use option::Option::{self, Some, None};
-use marker::{Copy, PhantomData, Send, Sized, Sync, Unsize};
+use marker::{PhantomData, Unsize};
 use mem;
 use nonzero::NonZero;
 
-use cmp::{PartialEq, Eq, Ord, PartialOrd};
 use cmp::Ordering::{self, Less, Equal, Greater};
 
 // FIXME #19649: intrinsic docs don't render, so these have no docs :(
diff --git a/src/libcore/result.rs b/src/libcore/result.rs
index 718fdf865a9..49eb5619bc6 100644
--- a/src/libcore/result.rs
+++ b/src/libcore/result.rs
@@ -236,14 +236,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use self::Result::{Ok, Err};
-
-use clone::Clone;
 use fmt;
-use iter::{Iterator, DoubleEndedIterator, FromIterator, ExactSizeIterator, IntoIterator};
-use iter::FusedIterator;
-use ops::FnOnce;
-use option::Option::{self, None, Some};
+use iter::{FromIterator, FusedIterator};
 
 /// `Result` is a type that represents either success (`Ok`) or failure (`Err`).
 ///
diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index 603f55a6e10..baa41aa7af5 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -33,24 +33,15 @@
 // * The `raw` and `bytes` submodules.
 // * Boilerplate trait implementations.
 
-use clone::Clone;
-use cmp::{Ordering, PartialEq, PartialOrd, Eq, Ord};
-use cmp::Ordering::{Less, Equal, Greater};
+use cmp::Ordering::{self, Less, Equal, Greater};
 use cmp;
-use convert::AsRef;
-use default::Default;
 use fmt;
 use intrinsics::assume;
 use iter::*;
-use ops::{FnMut, self};
-use ops::RangeFull;
-use option::Option;
-use option::Option::{None, Some};
-use result::Result;
-use result::Result::{Ok, Err};
+use ops::{self, RangeFull};
 use ptr;
 use mem;
-use marker::{Copy, Send, Sync, self};
+use marker;
 use iter_private::TrustedRandomAccess;
 
 #[repr(C)]
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 5dc5880e310..18e43c02c64 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -18,18 +18,10 @@ use self::pattern::Pattern;
 use self::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher};
 
 use char;
-use clone::Clone;
-use convert::AsRef;
-use default::Default;
 use fmt;
-use iter::ExactSizeIterator;
-use iter::{Map, Cloned, Iterator, DoubleEndedIterator, FusedIterator};
-use marker::Sized;
+use iter::{Map, Cloned, FusedIterator};
 use mem;
-use ops::{Fn, FnMut, FnOnce};
-use option::Option::{self, None, Some};
-use result::Result::{self, Ok, Err};
-use slice::{self, SliceExt};
+use slice;
 
 pub mod pattern;
 
@@ -1338,11 +1330,9 @@ Section: Trait implementations
 */
 
 mod traits {
-    use cmp::{Ord, Ordering, PartialEq, PartialOrd, Eq};
-    use option::Option;
-    use option::Option::Some;
+    use cmp::Ordering;
     use ops;
-    use str::{StrExt, eq_slice};
+    use str::eq_slice;
 
     #[stable(feature = "rust1", since = "1.0.0")]
     impl Ord for str {
diff --git a/src/libcore/str/pattern.rs b/src/libcore/str/pattern.rs
index 53804c611e6..7dced2ba751 100644
--- a/src/libcore/str/pattern.rs
+++ b/src/libcore/str/pattern.rs
@@ -17,8 +17,6 @@
             reason = "API not fully fleshed out and ready to be stabilized",
             issue = "27721")]
 
-use prelude::v1::*;
-
 use cmp;
 use fmt;
 use usize;
diff --git a/src/libcore/sync/atomic.rs b/src/libcore/sync/atomic.rs
index bd62879c1a5..75ddd2021a8 100644
--- a/src/libcore/sync/atomic.rs
+++ b/src/libcore/sync/atomic.rs
@@ -79,14 +79,8 @@
 
 use self::Ordering::*;
 
-use marker::{Send, Sync};
-
 use intrinsics;
 use cell::UnsafeCell;
-
-use result::Result::{self, Ok, Err};
-
-use default::Default;
 use fmt;
 
 /// A boolean type which can be safely shared between threads.
diff --git a/src/libcore/tuple.rs b/src/libcore/tuple.rs
index abaabfd129b..c3608b60a31 100644
--- a/src/libcore/tuple.rs
+++ b/src/libcore/tuple.rs
@@ -10,12 +10,8 @@
 
 // See src/libstd/primitive_docs.rs for documentation.
 
-use clone::Clone;
 use cmp::*;
 use cmp::Ordering::*;
-use default::Default;
-use option::Option;
-use option::Option::Some;
 
 // FIXME(#19630) Remove this work-around
 macro_rules! e {