45 lines
955 B
Rust
45 lines
955 B
Rust
#![feature(specialization)]
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trait Foo: Copy + ToString {}
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impl<T: Copy + ToString> Foo for T {}
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fn hide<T: Foo>(x: T) -> impl Foo {
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x
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}
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trait Leak: Sized {
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type T;
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fn leak(self) -> Self::T;
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}
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impl<T> Leak for T {
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default type T = ();
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default fn leak(self) -> Self::T { panic!() }
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}
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impl Leak for i32 {
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type T = i32;
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fn leak(self) -> i32 { self }
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}
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fn main() {
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let _: u32 = hide(0_u32);
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//~^ ERROR mismatched types
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//~| expected type `u32`
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//~| found type `impl Foo`
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//~| expected u32, found opaque type
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let _: i32 = Leak::leak(hide(0_i32));
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//~^ ERROR mismatched types
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//~| expected type `i32`
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//~| found type `<impl Foo as Leak>::T`
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//~| expected i32, found associated type
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let mut x = (hide(0_u32), hide(0_i32));
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x = (x.1,
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//~^ ERROR mismatched types
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//~| expected u32, found i32
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x.0);
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//~^ ERROR mismatched types
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//~| expected i32, found u32
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}
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