//@revisions: string unit atomic #![feature(type_alias_impl_trait)] //! Check that we do not cause cycle errors when trying to //! obtain information about interior mutability of an opaque type. //! This used to happen, because when the body-analysis failed, we //! checked the type instead, but the constant was also defining the //! hidden type of the opaque type. Thus we ended up relying on the //! result of our analysis to compute the result of our analysis. pub type Foo = impl Sized; #[cfg(string)] #[define_opaque(Foo)] const fn foo() -> Foo { String::new() } #[cfg(atomic)] #[define_opaque(Foo)] const fn foo() -> Foo { std::sync::atomic::AtomicU8::new(42) } #[cfg(unit)] #[define_opaque(Foo)] const fn foo() -> Foo {} const FOO: Foo = foo(); const BAR: () = { let _: &'static _ = &FOO; //[string,atomic,unit]~^ ERROR: destructor of `Foo` cannot be evaluated at compile-time }; const BAZ: &Foo = &FOO; //[atomic]~^ ERROR: interior mutable shared borrows of temporaries fn main() { let _: &'static _ = &FOO; //[string,atomic,unit]~^ ERROR: temporary value dropped while borrowed }