rust/src/test/compile-fail/unboxed-closure-sugar-wrong-trait.rs
Patrick Walton 7c00d77e8b librustc: Implement the syntax in the RFC for unboxed closure sugar.
Part of issue #16640. I am leaving this issue open to handle parsing of
higher-rank lifetimes in traits.

This change breaks code that used unboxed closures:

* Instead of `F:|&: int| -> int`, write `F:Fn(int) -> int`.

* Instead of `F:|&mut: int| -> int`, write `F:FnMut(int) -> int`.

* Instead of `F:|: int| -> int`, write `F:FnOnce(int) -> int`.

[breaking-change]
2014-09-18 16:31:58 -07:00

18 lines
609 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.
trait Trait {}
fn f<F:Trait(int) -> int>(x: F) {}
//~^ ERROR unboxed function trait must be one of `Fn`, `FnMut`, or `FnOnce`
fn main() {}