rust/src/test/ui/unboxed-closures/unboxed-closures-mutated-upvar-from-fn-closure.rs
2018-12-25 21:08:33 -07:00

19 lines
425 B
Rust

// revisions: ast mir
//[mir]compile-flags: -Z borrowck=mir
// Test that a by-ref `FnMut` closure gets an error when it tries to
// mutate a value.
fn call<F>(f: F) where F : Fn() {
f();
}
fn main() {
let mut counter = 0;
call(|| {
counter += 1;
//[ast]~^ ERROR cannot assign to data in a captured outer variable in an `Fn` closure
//[mir]~^^ ERROR cannot assign to `counter`
});
}