rust/src/test/compile-fail/regions-lifetime-bounds-on-fns.rs
2015-01-08 11:02:24 -05:00

40 lines
1.3 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.
fn a<'a, 'b:'a>(x: &mut &'a isize, y: &mut &'b isize) {
// Note: this is legal because of the `'b:'a` declaration.
*x = *y;
}
fn b<'a, 'b>(x: &mut &'a isize, y: &mut &'b isize) {
// Illegal now because there is no `'b:'a` declaration.
*x = *y; //~ ERROR cannot infer
}
fn c<'a,'b>(x: &mut &'a isize, y: &mut &'b isize) {
// Here we try to call `foo` but do not know that `'a` and `'b` are
// related as required.
a(x, y); //~ ERROR cannot infer
}
fn d() {
// 'a and 'b are early bound in the function `a` because they appear
// inconstraints:
let _: fn(&mut &isize, &mut &isize) = a; //~ ERROR mismatched types
}
fn e() {
// 'a and 'b are late bound in the function `b` because there are
// no constraints:
let _: fn(&mut &isize, &mut &isize) = b;
}
fn main() { }