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// 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]);
}
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