51 lines
1.4 KiB
Rust
51 lines
1.4 KiB
Rust
// Copyright 2014 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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// Tests that a closure which requires mutable access to the referent
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// of an `&mut` requires a "unique" borrow -- that is, the variable to
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// be borrowed (here, `x`) will not be borrowed *mutably*, but
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// may be *immutable*, but we cannot allow
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// multiple borrows.
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fn get(x: &isize) -> isize {
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*x
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}
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fn set(x: &mut isize) -> isize {
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*x
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}
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fn a(x: &mut isize) {
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let c1 = || get(x);
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let c2 = || get(x);
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}
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fn b(x: &mut isize) {
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let c1 = || get(x);
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let c2 = || set(x); //~ ERROR closure requires unique access to `x`
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}
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fn c(x: &mut isize) {
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let c1 = || get(x);
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let c2 = || { get(x); set(x); }; //~ ERROR closure requires unique access to `x`
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}
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fn d(x: &mut isize) {
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let c1 = || set(x);
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let c2 = || set(x); //~ ERROR two closures require unique access to `x` at the same time
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}
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fn e(x: &mut isize) {
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let c1 = || x = panic!(); //~ ERROR closure cannot assign to immutable argument
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}
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fn main() {
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}
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