rust/src/test/compile-fail/kindck-freeze.rs
2013-11-26 08:19:00 -08:00

57 lines
1.9 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.
// Test which of the builtin types are considered freezeable.
fn assert_freeze<T:Freeze>() { }
trait Dummy { }
fn test<'a,T,U:Freeze>(_: &'a int) {
// lifetime pointers are ok...
assert_freeze::<&'static int>();
assert_freeze::<&'a int>();
assert_freeze::<&'a str>();
assert_freeze::<&'a [int]>();
// ...unless they are mutable
assert_freeze::<&'static mut int>(); //~ ERROR does not fulfill `Freeze`
assert_freeze::<&'a mut int>(); //~ ERROR does not fulfill `Freeze`
// ~ pointers are ok
assert_freeze::<~int>();
assert_freeze::<~str>();
assert_freeze::<~[int]>();
// but not if they own a bad thing
assert_freeze::<~&'a mut int>(); //~ ERROR does not fulfill `Freeze`
// careful with object types, who knows what they close over...
assert_freeze::<&'a Dummy>(); //~ ERROR does not fulfill `Freeze`
assert_freeze::<~Dummy>(); //~ ERROR does not fulfill `Freeze`
// ...unless they are properly bounded
assert_freeze::<&'a Dummy:Freeze>();
assert_freeze::<&'static Dummy:Freeze>();
assert_freeze::<~Dummy:Freeze>();
// ...but even then the pointer overrides
assert_freeze::<&'a mut Dummy:Freeze>(); //~ ERROR does not fulfill `Freeze`
// closures are like an `&mut` object
assert_freeze::<||>(); //~ ERROR does not fulfill `Freeze`
// unsafe ptrs are ok unless they point at unfreezeable things
assert_freeze::<*int>();
assert_freeze::<*&'a mut int>(); //~ ERROR does not fulfill `Freeze`
}
fn main() {
}