rust/src/test/compile-fail/unboxed-closures-wrong-trait.rs
Patrick Walton 8d27232141 librustc: Tie up loose ends in unboxed closures.
This patch primarily does two things: (1) it prevents lifetimes from
leaking out of unboxed closures; (2) it allows unboxed closure type
notation, call notation, and construction notation to construct closures
matching any of the three traits.

This breaks code that looked like:

    let mut f;
    {
        let x = &5i;
        f = |&mut:| *x + 10;
    }

Change this code to avoid having a reference escape. For example:

    {
        let x = &5i;
        let mut f; // <-- move here to avoid dangling reference
        f = |&mut:| *x + 10;
    }

I believe this is enough to consider unboxed closures essentially
implemented. Further issues (for example, higher-rank lifetimes) should
be filed as followups.

Closes #14449.

[breaking-change]
2014-08-14 08:53:25 -07:00

23 lines
718 B
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.
#![feature(lang_items, overloaded_calls, unboxed_closures)]
fn c<F:|: int, int| -> int>(f: F) -> int {
f(5, 6)
}
fn main() {
let z: int = 7;
assert_eq!(c(|&: x: int, y| x + y + z), 10);
//~^ ERROR failed to find an implementation
}