rust/tests/ui/unboxed-closures/unboxed-closure-sugar-equiv.rs
2023-01-11 09:32:08 +00:00

49 lines
2.0 KiB
Rust

// Test that the unboxed closure sugar can be used with an arbitrary
// struct type and that it is equivalent to the same syntax using
// angle brackets. This test covers only simple types and in
// particular doesn't test bound regions.
#![feature(unboxed_closures)]
#![allow(dead_code)]
trait Foo<T> {
type Output;
fn dummy(&self, t: T, u: Self::Output);
}
trait Eq<X: ?Sized> { }
impl<X: ?Sized> Eq<X> for X { }
fn eq<A: ?Sized,B: ?Sized +Eq<A>>() { }
fn test<'a,'b>() {
// No errors expected:
eq::< dyn Foo<(),Output=()>, dyn Foo() >();
eq::< dyn Foo<(isize,),Output=()>, dyn Foo(isize) >();
eq::< dyn Foo<(isize,usize),Output=()>, dyn Foo(isize,usize) >();
eq::< dyn Foo<(isize,usize),Output=usize>, dyn Foo(isize,usize) -> usize >();
eq::< dyn Foo<(&'a isize,&'b usize),Output=usize>, dyn Foo(&'a isize,&'b usize) -> usize >();
// Test that anonymous regions in `()` form are equivalent
// to fresh bound regions, and that we can intermingle
// named and anonymous as we choose:
eq::< dyn for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
dyn for<'x,'y> Foo(&'x isize,&'y usize) -> usize >();
eq::< dyn for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
dyn for<'x> Foo(&'x isize,&usize) -> usize >();
eq::< dyn for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
dyn for<'y> Foo(&isize,&'y usize) -> usize >();
eq::< dyn for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
dyn Foo(&isize,&usize) -> usize >();
// lifetime elision
eq::< dyn for<'x> Foo<(&'x isize,), Output=&'x isize>,
dyn Foo(&isize) -> &isize >();
// Errors expected:
eq::< dyn Foo<(),Output=()>,
dyn Foo(char) >();
//~^ ERROR E0277
}
fn main() { }