mirror of https://github.com/rust-lang/rust
55 lines
1.1 KiB
Rust
55 lines
1.1 KiB
Rust
// 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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c1();
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c2();
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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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c1;
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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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c1;
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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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c1;
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}
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fn e(x: &'static mut isize) {
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let c1 = |y: &'static mut isize| x = y;
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//~^ ERROR cannot assign to `x`, as it is not declared as mutable
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c1;
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}
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fn f(x: &'static mut isize) {
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let c1 = || x = panic!(); // OK assignment is unreachable.
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c1;
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}
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fn main() {
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}
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