rust/src/test/run-pass/builtin-superkinds-capabilities.rs
Niko Matsakis 9e3d0b002a librustc: Remove the fallback to int from typechecking.
This breaks a fair amount of code. The typical patterns are:

* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;

* `println!("{}", 3)`: change to `println!("{}", 3i)`;

* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.

RFC #30. Closes #6023.

[breaking-change]
2014-06-24 17:18:48 -07:00

28 lines
922 B
Rust

// Copyright 2013 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 "capabilities" granted by traits that inherit from super-
// builtin-kinds, e.g., if a trait requires Send to implement, then
// at usage site of that trait, we know we have the Send capability.
trait Foo : Send { }
impl <T: Send> Foo for T { }
fn foo<T: Foo>(val: T, chan: Sender<T>) {
chan.send(val);
}
pub fn main() {
let (tx, rx): (Sender<int>, Receiver<int>) = channel();
foo(31337i, tx);
assert!(rx.recv() == 31337i);
}