mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-24 07:44:10 +00:00
17 lines
323 B
Rust
17 lines
323 B
Rust
// run-pass
|
|
struct A<F: FnOnce()->T,T>(F::Output);
|
|
struct B<F: FnOnce()->T,T>(A<F,T>);
|
|
|
|
// Removing Option causes it to compile.
|
|
fn foo<T,F: FnOnce()->T>(f: F) -> Option<B<F,T>> {
|
|
Some(B(A(f())))
|
|
}
|
|
|
|
fn main() {
|
|
let v = (|| foo(||4))();
|
|
match v {
|
|
Some(B(A(4))) => {},
|
|
_ => unreachable!()
|
|
}
|
|
}
|