rust/tests/ui/impl-trait/equality.rs

44 lines
754 B
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
}
fn two(x: bool) -> impl Foo {
if x {
return 1_i32;
}
0_u32
//~^ ERROR mismatched types
//~| expected `i32`, found `u32`
}
fn sum_to(n: u32) -> impl Foo {
if n == 0 {
0
} else {
n + sum_to(n - 1)
//~^ ERROR cannot add `impl Foo` to `u32`
}
}
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() {
}