39 lines
924 B
Rust
39 lines
924 B
Rust
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// A regression test for #97156
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type One = for<'a> fn(&'a (), &'a ());
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type Two = for<'a, 'b> fn(&'a (), &'b ());
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mod my_api {
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use std::any::Any;
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use std::marker::PhantomData;
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pub struct Foo<T: 'static> {
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a: &'static dyn Any,
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_p: PhantomData<*mut T>, // invariant, the type of the `dyn Any`
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}
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impl<T: 'static> Foo<T> {
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pub fn deref(&self) -> &'static T {
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match self.a.downcast_ref::<T>() {
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None => unsafe { std::hint::unreachable_unchecked() },
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Some(a) => a,
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}
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}
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pub fn new(a: T) -> Foo<T> {
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Foo::<T> { a: Box::leak(Box::new(a)), _p: PhantomData }
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}
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}
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}
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use my_api::*;
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fn main() {
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let foo = Foo::<One>::new((|_, _| ()) as One);
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foo.deref();
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let foo: Foo<Two> = foo;
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//~^ ERROR mismatched types [E0308]
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//~| ERROR mismatched types [E0308]
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foo.deref();
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}
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