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// run-pass
// needs-unwind
#![feature(fn_traits)]
#![feature(never_type)]
use std::panic;
fn foo(x: u32, y: u32) -> u32 { x/y }
fn foo_diverges() -> ! { panic!() }
fn test_fn_ptr<T>(mut t: T)
where T: Fn(u32, u32) -> u32,
{
let as_fn = <T as Fn<(u32, u32)>>::call;
assert_eq!(as_fn(&t, (9, 3)), 3);
let as_fn_mut = <T as FnMut<(u32, u32)>>::call_mut;
assert_eq!(as_fn_mut(&mut t, (18, 3)), 6);
let as_fn_once = <T as FnOnce<(u32, u32)>>::call_once;
assert_eq!(as_fn_once(t, (24, 3)), 8);
}
fn assert_panics<F>(f: F) where F: FnOnce() {
let f = panic::AssertUnwindSafe(f);
let result = panic::catch_unwind(move || {
f.0()
});
if let Ok(..) = result {
panic!("diverging function returned");
}
}
fn test_fn_ptr_panic<T>(mut t: T)
where T: Fn() -> !
{
let as_fn = <T as Fn<()>>::call;
assert_panics(|| as_fn(&t, ()));
let as_fn_mut = <T as FnMut<()>>::call_mut;
assert_panics(|| as_fn_mut(&mut t, ()));
let as_fn_once = <T as FnOnce<()>>::call_once;
assert_panics(|| as_fn_once(t, ()));
}
fn main() {
test_fn_ptr(foo);
test_fn_ptr(foo as fn(u32, u32) -> u32);
test_fn_ptr_panic(foo_diverges);
test_fn_ptr_panic(foo_diverges as fn() -> !);
}
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