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|
// Issue #29793, big regression test: do not let borrows of
// parameters to ever be returned (expanded with exploration of
// variations).
//
// This is the version of the test that actually exposed unsound
// behavior (because the improperly accepted closure was actually
// able to be invoked).
struct WrapA<F>(Option<F>);
impl<F> WrapA<F> {
fn new() -> WrapA<F> {
WrapA(None)
}
fn set(mut self, f: F) -> Self {
self.0 = Some(f);
self
}
}
struct WrapB<F>(Option<F>);
impl<F> WrapB<F> {
fn new() -> WrapB<F> {
WrapB(None)
}
fn set(mut self, f: F) -> Self {
self.0 = Some(f);
self
}
}
trait DoStuff : Sized {
fn handle(self);
}
impl<F, T> DoStuff for WrapA<F>
where F: FnMut(usize, usize) -> T, T: DoStuff {
fn handle(mut self) {
if let Some(ref mut f) = self.0 {
let x = f(1, 2);
let _foo = [0usize; 16];
x.handle();
}
}
}
impl<F> DoStuff for WrapB<F> where F: FnMut(bool) -> usize {
fn handle(mut self) {
if let Some(ref mut f) = self.0 {
println!("{}", f(true));
}
}
}
impl<F, T> WrapA<F>
where F: FnMut(usize, usize) -> T, T: DoStuff {
fn handle_ref(&mut self) {
if let Some(ref mut f) = self.0 {
let x = f(1, 2);
}
}
}
fn main() {
let mut w = WrapA::new().set(|x: usize, y: usize| {
WrapB::new().set(|t: bool| if t { x } else { y }) // (separate errors for `x` vs `y`)
//~^ ERROR closure may outlive the current function
//~| ERROR closure may outlive the current function
});
w.handle(); // This works
// w.handle_ref(); // This doesn't
}
|
