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|
#![feature(coroutines, negative_impls, rustc_attrs, stmt_expr_attributes)]
macro_rules! type_combinations {
(
$( $name:ident => { $( $tt:tt )* } );* $(;)?
) => { $(
mod $name {
$( $tt )*
impl !Sync for Client {}
impl !Send for Client {}
}
// Struct update syntax. This fails because the Client used in the update is considered
// dropped *after* the yield.
{
let g = #[coroutine] move || match drop($name::Client { ..$name::Client::default() }) {
//~^ `significant_drop::Client` which is not `Send`
//~| `insignificant_dtor::Client` which is not `Send`
//~| `derived_drop::Client` which is not `Send`
_ => yield,
};
assert_send(g);
//~^ ERROR cannot be sent between threads
//~| ERROR cannot be sent between threads
//~| ERROR cannot be sent between threads
}
// Simple owned value. This works because the Client is considered moved into `drop`,
// even though the temporary expression doesn't end until after the yield.
{
let g = #[coroutine] move || match drop($name::Client::default()) {
_ => yield,
};
assert_send(g);
}
)* }
}
fn assert_send<T: Send>(_thing: T) {}
fn main() {
type_combinations!(
// OK
copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
// NOT OK: MIR borrowck thinks that this is used after the yield, even though
// this has no `Drop` impl and only the drops of the fields are observable.
// FIXME: this should compile.
derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
// NOT OK
significant_drop => {
#[derive(Default)]
pub struct Client;
impl Drop for Client {
fn drop(&mut self) {}
}
};
// NOT OK (we need to agree with MIR borrowck)
insignificant_dtor => {
#[derive(Default)]
#[rustc_insignificant_dtor]
pub struct Client;
impl Drop for Client {
fn drop(&mut self) {}
}
};
);
}
|
