33 lines
511 B
Rust
33 lines
511 B
Rust
|
pub trait Element<S> {
|
||
|
|
type Array;
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<T> Element<()> for T {
|
||
|
|
type Array = T;
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<T: Element<S>, S> Element<[S; 3]> for T {
|
||
|
|
type Array = [T::Array; 3];
|
||
|
|
}
|
||
|
|
|
||
|
|
trait Foo<I>
|
||
|
|
where
|
||
|
|
u8: Element<I>,
|
||
|
|
{
|
||
|
|
fn foo(self, x: <u8 as Element<I>>::Array);
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<I> Foo<I> for u16
|
||
|
|
where
|
||
|
|
u8: Element<I>,
|
||
|
|
{
|
||
|
|
fn foo(self, _: <u8 as Element<I>>::Array) {}
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
let b: [u8; 3] = [0u8; 3];
|
||
|
|
|
||
|
|
0u16.foo(b); //~ ERROR type annotations needed
|
||
|
|
//<u16 as Foo<[(); 3]>>::foo(0u16, b);
|
||
|
|
}
|