mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-23 23:34:48 +00:00
45 lines
1.0 KiB
Rust
45 lines
1.0 KiB
Rust
#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
|
|
|
|
trait Foo: Copy + ToString {}
|
|
|
|
impl<T: Copy + ToString> Foo for T {}
|
|
|
|
fn hide<T: Foo>(x: T) -> impl Foo {
|
|
x
|
|
}
|
|
|
|
trait Leak: Sized {
|
|
type T;
|
|
fn leak(self) -> Self::T;
|
|
}
|
|
impl<T> Leak for T {
|
|
default type T = ();
|
|
default fn leak(self) -> Self::T { panic!() }
|
|
}
|
|
impl Leak for i32 {
|
|
type T = i32;
|
|
fn leak(self) -> i32 { self }
|
|
}
|
|
|
|
fn main() {
|
|
let _: u32 = hide(0_u32);
|
|
//~^ ERROR mismatched types
|
|
//~| expected type `u32`
|
|
//~| found opaque type `impl Foo`
|
|
//~| expected `u32`, found opaque type
|
|
|
|
let _: i32 = Leak::leak(hide(0_i32));
|
|
//~^ ERROR mismatched types
|
|
//~| expected type `i32`
|
|
//~| found associated type `<impl Foo as Leak>::T`
|
|
//~| expected `i32`, found associated type
|
|
|
|
let mut x = (hide(0_u32), hide(0_i32));
|
|
x = (x.1,
|
|
//~^ ERROR mismatched types
|
|
//~| expected `u32`, found `i32`
|
|
x.0);
|
|
//~^ ERROR mismatched types
|
|
//~| expected `i32`, found `u32`
|
|
}
|