rust/tests/ui/coroutine/resume-arg-size.rs
Oli Scherer aef0f4024a Error on using yield without also using #[coroutine] on the closure
And suggest adding the `#[coroutine]` to the closure
2024-04-24 08:05:29 +00:00

32 lines
735 B
Rust

#![feature(coroutines, stmt_expr_attributes)]
#![allow(dropping_copy_types)]
//@ run-pass
use std::mem::size_of_val;
fn main() {
// Coroutine taking a `Copy`able resume arg.
let gen_copy = #[coroutine]
|mut x: usize| {
loop {
drop(x);
x = yield;
}
};
// Coroutine taking a non-`Copy` resume arg.
let gen_move = #[coroutine]
|mut x: Box<usize>| {
loop {
drop(x);
x = yield;
}
};
// Neither of these coroutines have the resume arg live across the `yield`, so they should be
// 1 Byte in size (only storing the discriminant)
assert_eq!(size_of_val(&gen_copy), 1);
assert_eq!(size_of_val(&gen_move), 1);
}