| // Copyright 2015 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 that we cannot mutate an outer variable that is not declared |
| // as `mut` through a closure. Also test that we CAN mutate a moved copy, |
| // unless this is a `Fn` closure. Issue #16749. |
| |
| #![feature(unboxed_closures)] |
| |
| use std::mem; |
| |
| fn to_fn<A,F:Fn<A>>(f: F) -> F { f } |
| fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } |
| |
| fn a() { |
| let n = 0; |
| let mut f = to_fn_mut(|| { //~ ERROR closure cannot assign |
| n += 1; |
| }); |
| } |
| |
| fn b() { |
| let mut n = 0; |
| let mut f = to_fn_mut(|| { |
| n += 1; // OK |
| }); |
| } |
| |
| fn c() { |
| let n = 0; |
| let mut f = to_fn_mut(move || { |
| // If we just did a straight-forward desugaring, this would |
| // compile, but we do something a bit more subtle, and hence |
| // we get an error. |
| n += 1; //~ ERROR cannot assign |
| }); |
| } |
| |
| fn d() { |
| let mut n = 0; |
| let mut f = to_fn_mut(move || { |
| n += 1; // OK |
| }); |
| } |
| |
| fn e() { |
| let n = 0; |
| let mut f = to_fn(move || { |
| n += 1; //~ ERROR cannot assign |
| }); |
| } |
| |
| fn f() { |
| let mut n = 0; |
| let mut f = to_fn(move || { |
| n += 1; //~ ERROR cannot assign |
| }); |
| } |
| |
| fn main() { } |