rust/src/test/run-pass/traits-multidispatch-infer-convert-target.rs
Niko Matsakis 389ef6601d Implement multidispatch and conditional dispatch. Because we do not
attempt to preserve crate concatenation, this is a backwards compatible
change.

Conflicts:
	src/librustc/middle/traits/select.rs
2014-10-09 17:19:50 -04:00

47 lines
1.1 KiB
Rust

// 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.
// Test that we can infer the Target based on the Self or vice versa.
use std::mem;
trait Convert<Target> {
fn convert(&self) -> Target;
}
impl Convert<u32> for i16 {
fn convert(&self) -> u32 {
*self as u32
}
}
impl Convert<i16> for u32 {
fn convert(&self) -> i16 {
*self as i16
}
}
fn test<T,U>(_: T, _: U, t_size: uint, u_size: uint)
where T : Convert<U>
{
assert_eq!(mem::size_of::<T>(), t_size);
assert_eq!(mem::size_of::<U>(), u_size);
}
fn main() {
// T = i16, U = u32
test(22_i16, 44, 2, 4);
test(22, 44_u32, 2, 4);
// T = u32, U = i16
test(22_u32, 44, 4, 2);
test(22, 44_i16, 4, 2);
}