| // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Check that you can cast between different pointers to trait objects |
| // whose vtable have the same kind (both lengths, or both trait pointers). |
| |
| trait Foo<T> { |
| fn foo(&self, _: T) -> u32 { 42 } |
| } |
| |
| trait Bar { |
| fn bar(&self) { println!("Bar!"); } |
| } |
| |
| impl<T> Foo<T> for () {} |
| impl Foo<u32> for u32 { fn foo(&self, _: u32) -> u32 { self+43 } } |
| impl Bar for () {} |
| |
| unsafe fn round_trip_and_call<'a>(t: *const (Foo<u32>+'a)) -> u32 { |
| let foo_e : *const Foo<u16> = t as *const _; |
| let r_1 = foo_e as *mut Foo<u32>; |
| |
| (&*r_1).foo(0) |
| } |
| |
| #[repr(C)] |
| struct FooS<T:?Sized>(T); |
| #[repr(C)] |
| struct BarS<T:?Sized>(T); |
| |
| fn foo_to_bar<T:?Sized>(u: *const FooS<T>) -> *const BarS<T> { |
| u as *const BarS<T> |
| } |
| |
| fn main() { |
| let x = 4u32; |
| let y : &Foo<u32> = &x; |
| let fl = unsafe { round_trip_and_call(y as *const Foo<u32>) }; |
| assert_eq!(fl, (43+4)); |
| |
| let s = FooS([0,1,2]); |
| let u: &FooS<[u32]> = &s; |
| let u: *const FooS<[u32]> = u; |
| let bar_ref : *const BarS<[u32]> = foo_to_bar(u); |
| let z : &BarS<[u32]> = unsafe{&*bar_ref}; |
| assert_eq!(&z.0, &[0,1,2]); |
| } |