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Diffstat (limited to 'compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs')
-rw-r--r-- | compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs b/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs new file mode 100644 index 000000000..d270fec6b --- /dev/null +++ b/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs @@ -0,0 +1,68 @@ +// Adapted from rustc run-pass test suite + +#![feature(arbitrary_self_types, unsize, coerce_unsized, dispatch_from_dyn)] + +use std::{ + ops::{Deref, CoerceUnsized, DispatchFromDyn}, + marker::Unsize, +}; + +struct Ptr<T: ?Sized>(Box<T>); + +impl<T: ?Sized> Deref for Ptr<T> { + type Target = T; + + fn deref(&self) -> &T { + &*self.0 + } +} + +impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {} +impl<T: Unsize<U> + ?Sized, U: ?Sized> DispatchFromDyn<Ptr<U>> for Ptr<T> {} + +struct Wrapper<T: ?Sized>(T); + +impl<T: ?Sized> Deref for Wrapper<T> { + type Target = T; + + fn deref(&self) -> &T { + &self.0 + } +} + +impl<T: CoerceUnsized<U>, U> CoerceUnsized<Wrapper<U>> for Wrapper<T> {} +impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<Wrapper<U>> for Wrapper<T> {} + + +trait Trait { + // This method isn't object-safe yet. Unsized by-value `self` is object-safe (but not callable + // without unsized_locals), but wrappers around `Self` currently are not. + // FIXME (mikeyhew) uncomment this when unsized rvalues object-safety is implemented + // fn wrapper(self: Wrapper<Self>) -> i32; + fn ptr_wrapper(self: Ptr<Wrapper<Self>>) -> i32; + fn wrapper_ptr(self: Wrapper<Ptr<Self>>) -> i32; + fn wrapper_ptr_wrapper(self: Wrapper<Ptr<Wrapper<Self>>>) -> i32; +} + +impl Trait for i32 { + fn ptr_wrapper(self: Ptr<Wrapper<Self>>) -> i32 { + **self + } + fn wrapper_ptr(self: Wrapper<Ptr<Self>>) -> i32 { + **self + } + fn wrapper_ptr_wrapper(self: Wrapper<Ptr<Wrapper<Self>>>) -> i32 { + ***self + } +} + +fn main() { + let pw = Ptr(Box::new(Wrapper(5))) as Ptr<Wrapper<dyn Trait>>; + assert_eq!(pw.ptr_wrapper(), 5); + + let wp = Wrapper(Ptr(Box::new(6))) as Wrapper<Ptr<dyn Trait>>; + assert_eq!(wp.wrapper_ptr(), 6); + + let wpw = Wrapper(Ptr(Box::new(Wrapper(7)))) as Wrapper<Ptr<Wrapper<dyn Trait>>>; + assert_eq!(wpw.wrapper_ptr_wrapper(), 7); +} |