blob: 212e7b1080216b07c39ed0d537a8137f8517e7f4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
// This doesn't work, because we don't flow information from opaque types
// into function arguments via the function's generic parameters
// FIXME(oli-obk): make `expected_inputs_for_expected_output` support this
#![feature(type_alias_impl_trait)]
fn reify_as() -> Thunk<impl FnOnce(Continuation) -> Continuation> {
Thunk::new(|mut cont| {
//~^ ERROR type annotations needed
cont.reify_as();
cont
})
}
type Tait = impl FnOnce(Continuation) -> Continuation;
fn reify_as_tait() -> Thunk<Tait> {
Thunk::new(|mut cont| {
//~^ ERROR type annotations needed
cont.reify_as();
cont
})
}
#[must_use]
struct Thunk<F>(F);
impl<F> Thunk<F> {
fn new(f: F) -> Self
where
F: ContFn,
{
Thunk(f)
}
}
trait ContFn {}
impl<F: FnOnce(Continuation) -> Continuation> ContFn for F {}
struct Continuation;
impl Continuation {
fn reify_as(&mut self) {}
}
fn main() {}
|
