58 lines
1.7 KiB
Rust
58 lines
1.7 KiB
Rust
// 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<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| { fail_unless!(x[*y] == *y); }
|
|
// Call a parameterized function
|
|
fail_unless!(length(x.clone()) == vec::len(x));
|
|
// Call a parameterized function, with type arguments that require
|
|
// a borrow
|
|
fail_unless!(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| { fail_unless!(z[*y] == *y); }
|
|
// Call a parameterized function
|
|
fail_unless!(length::<int, &[int]>(z) == vec::len(z));
|
|
}
|