rust/tests/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.rs
2023-01-11 09:32:08 +00:00

21 lines
528 B
Rust

// Test that we are able to infer a suitable kind for this closure
// that is just called (`FnMut`).
fn main() {
let mut counter = 0;
// Here this must be inferred to FnMut so that it can mutate counter,
// but we forgot the mut.
let tick1 = || {
counter += 1;
};
// In turn, tick2 must be inferred to FnMut so that it can call
// tick1, but we forgot the mut.
let tick2 = || {
tick1(); //~ ERROR cannot borrow `tick1` as mutable
};
tick2(); //~ ERROR cannot borrow
}