rust/src/test/run-pass/trait-generic.rs
2013-08-30 15:10:55 -07:00

53 lines
1.4 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.
// xfail-fast
trait to_str {
fn to_string(&self) -> ~str;
}
impl to_str for int {
fn to_string(&self) -> ~str { self.to_str() }
}
impl to_str for ~str {
fn to_string(&self) -> ~str { self.clone() }
}
impl to_str for () {
fn to_string(&self) -> ~str { ~"()" }
}
trait map<T> {
fn map<U>(&self, f: &fn(&T) -> U) -> ~[U];
}
impl<T> map<T> for ~[T] {
fn map<U>(&self, f: &fn(&T) -> U) -> ~[U] {
let mut r = ~[];
// FIXME: #7355 generates bad code with VecIterator
for i in range(0u, self.len()) {
r.push(f(&self[i]));
}
r
}
}
fn foo<U, T: map<U>>(x: T) -> ~[~str] {
x.map(|_e| ~"hi" )
}
fn bar<U:to_str,T:map<U>>(x: T) -> ~[~str] {
x.map(|_e| _e.to_string() )
}
pub fn main() {
assert_eq!(foo(~[1]), ~[~"hi"]);
assert_eq!(bar::<int, ~[int]>(~[4, 5]), ~[~"4", ~"5"]);
assert_eq!(bar::<~str, ~[~str]>(~[~"x", ~"y"]), ~[~"x", ~"y"]);
assert_eq!(bar::<(), ~[()]>(~[()]), ~[~"()"]);
}