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//@ check-pass
//@ revisions: old next
//@[next] compile-flags: -Znext-solver
#![feature(ptr_metadata)]
use std::ptr::{self, Pointee};
fn cast_same_meta<T: ?Sized, U: ?Sized>(ptr: *const T) -> *const U
where
T: Pointee<Metadata = <U as Pointee>::Metadata>,
{
let (thin, meta) = ptr.to_raw_parts();
ptr::from_raw_parts(thin, meta)
}
struct Wrapper<T: ?Sized>(T);
// normalize `Wrapper<T>::Metadata` -> `T::Metadata`
fn wrapper_to_tail<T: ?Sized>(ptr: *const T) -> *const Wrapper<T> {
cast_same_meta(ptr)
}
// normalize `Wrapper<T>::Metadata` -> `T::Metadata` -> `()`
fn wrapper_to_unit<T>(ptr: *const ()) -> *const Wrapper<T> {
cast_same_meta(ptr)
}
trait Project {
type Assoc: ?Sized;
}
struct WrapperProject<T: ?Sized + Project>(T::Assoc);
// normalize `WrapperProject<T>::Metadata` -> `T::Assoc::Metadata`
fn wrapper_project_tail<T: ?Sized + Project>(ptr: *const T::Assoc) -> *const WrapperProject<T> {
cast_same_meta(ptr)
}
// normalize `WrapperProject<T>::Metadata` -> `T::Assoc::Metadata` -> `()`
fn wrapper_project_unit<T: ?Sized + Project>(ptr: *const ()) -> *const WrapperProject<T>
where
T::Assoc: Sized,
{
cast_same_meta(ptr)
}
// normalize `<[T] as Pointee>::Metadata` -> `usize`, even if `[T]: Sized`
fn sized_slice<T>(ptr: *const [T]) -> *const str
where
[T]: Sized,
{
cast_same_meta(ptr)
}
fn main() {}
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