rust/tests/ui/impl-trait/auto-trait-leak-rpass.rs
2024-02-16 20:02:50 +00:00

22 lines
425 B
Rust

//@ run-pass
// Fast path, main can see the concrete type returned.
fn before() -> impl FnMut(i32) {
let mut p = Box::new(0);
move |x| *p = x
}
fn send<T: Send>(_: T) {}
fn main() {
send(before());
send(after());
}
// Deferred path, main has to wait until typeck finishes,
// to check if the return type of after is Send.
fn after() -> impl FnMut(i32) {
let mut p = Box::new(0);
move |x| *p = x
}