68 lines
1.6 KiB
Rust
68 lines
1.6 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Test that we cannot mutate an outer variable that is not declared
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// as `mut` through a closure. Also test that we CAN mutate a moved copy,
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// unless this is a `Fn` closure. Issue #16749.
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#![feature(unboxed_closures)]
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use std::mem;
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fn to_fn<A,F:Fn<A>>(f: F) -> F { f }
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fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f }
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fn a() {
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let n = 0;
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let mut f = to_fn_mut(|| { //~ ERROR closure cannot assign
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n += 1;
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});
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}
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fn b() {
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let mut n = 0;
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let mut f = to_fn_mut(|| {
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n += 1; // OK
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});
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}
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fn c() {
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let n = 0;
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let mut f = to_fn_mut(move || {
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// If we just did a straight-forward desugaring, this would
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// compile, but we do something a bit more subtle, and hence
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// we get an error.
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n += 1; //~ ERROR cannot assign
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});
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}
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fn d() {
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let mut n = 0;
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let mut f = to_fn_mut(move || {
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n += 1; // OK
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});
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}
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fn e() {
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let n = 0;
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let mut f = to_fn(move || {
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n += 1; //~ ERROR cannot assign
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});
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}
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fn f() {
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let mut n = 0;
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let mut f = to_fn(move || {
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n += 1; //~ ERROR cannot assign
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});
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}
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fn main() { }
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