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// Copyright 2012 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.
// Tests that type assignability is used to search for instances when
// making method calls, but only if there aren't any matches without
// it.
trait iterable<A> {
fn iterate(&self, blk: &fn(x: &A) -> bool);
}
impl<'self,A> iterable<A> for &'self [A] {
fn iterate(&self, f: &fn(x: &A) -> bool) {
for vec::each(*self) |e| {
if !f(e) { break; }
}
}
}
impl<A> iterable<A> for ~[A] {
fn iterate(&self, f: &fn(x: &A) -> bool) {
for vec::each(*self) |e| {
if !f(e) { break; }
}
}
}
fn length<A, T: iterable<A>>(x: T) -> uint {
let mut len = 0;
for x.iterate() |_y| { len += 1 }
return len;
}
pub fn main() {
let x = ~[0,1,2,3];
// Call a method
for x.iterate() |y| { assert!(x[*y] == *y); }
// Call a parameterized function
assert!(length(x.clone()) == vec::len(x));
// Call a parameterized function, with type arguments that require
// a borrow
assert!(length::<int, &[int]>(x) == vec::len(x));
// Now try it with a type that *needs* to be borrowed
let z = [0,1,2,3];
// Call a method
for z.iterate() |y| { assert!(z[*y] == *y); }
// Call a parameterized function
assert!(length::<int, &[int]>(z) == vec::len(z));
}
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