77 lines
2.1 KiB
Rust
77 lines
2.1 KiB
Rust
|
// 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.
|
||
|
|
|
||
|
|
#![feature(rustc_attrs, coerce_unsized, unsize)]
|
||
|
|
|
||
|
|
use std::ops::CoerceUnsized;
|
||
|
|
use std::marker::Unsize;
|
||
|
|
|
||
|
|
#[rustc_mir]
|
||
|
|
fn identity_coercion(x: &(Fn(u32)->u32 + Send)) -> &Fn(u32)->u32 {
|
||
|
|
x
|
||
|
|
}
|
||
|
|
#[rustc_mir]
|
||
|
|
fn fn_coercions(f: &fn(u32) -> u32) ->
|
||
|
|
(unsafe fn(u32) -> u32,
|
||
|
|
&(Fn(u32) -> u32+Send))
|
||
|
|
{
|
||
|
|
(*f, f)
|
||
|
|
}
|
||
|
|
|
||
|
|
#[rustc_mir]
|
||
|
|
fn simple_array_coercion(x: &[u8; 3]) -> &[u8] { x }
|
||
|
|
|
||
|
|
fn square(a: u32) -> u32 { a * a }
|
||
|
|
|
||
|
|
#[derive(PartialEq,Eq)]
|
||
|
|
struct PtrWrapper<'a, T: 'a+?Sized>(u32, u32, (), &'a T);
|
||
|
|
impl<'a, T: ?Sized+Unsize<U>, U: ?Sized>
|
||
|
|
CoerceUnsized<PtrWrapper<'a, U>> for PtrWrapper<'a, T> {}
|
||
|
|
|
||
|
|
struct TrivPtrWrapper<'a, T: 'a+?Sized>(&'a T);
|
||
|
|
impl<'a, T: ?Sized+Unsize<U>, U: ?Sized>
|
||
|
|
CoerceUnsized<TrivPtrWrapper<'a, U>> for TrivPtrWrapper<'a, T> {}
|
||
|
|
|
||
|
|
#[rustc_mir]
|
||
|
|
fn coerce_ptr_wrapper(p: PtrWrapper<[u8; 3]>) -> PtrWrapper<[u8]> {
|
||
|
|
p
|
||
|
|
}
|
||
|
|
|
||
|
|
#[rustc_mir]
|
||
|
|
fn coerce_triv_ptr_wrapper(p: TrivPtrWrapper<[u8; 3]>) -> TrivPtrWrapper<[u8]> {
|
||
|
|
p
|
||
|
|
}
|
||
|
|
|
||
|
|
#[rustc_mir]
|
||
|
|
fn coerce_fat_ptr_wrapper(p: PtrWrapper<Fn(u32) -> u32+Send>)
|
||
|
|
-> PtrWrapper<Fn(u32) -> u32> {
|
||
|
|
p
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
let a = [0,1,2];
|
||
|
|
let square_local : fn(u32) -> u32 = square;
|
||
|
|
let (f,g) = fn_coercions(&square_local);
|
||
|
|
assert_eq!(f as usize, square as usize);
|
||
|
|
assert_eq!(g(4), 16);
|
||
|
|
assert_eq!(identity_coercion(g)(5), 25);
|
||
|
|
|
||
|
|
assert_eq!(simple_array_coercion(&a), &a);
|
||
|
|
let w = coerce_ptr_wrapper(PtrWrapper(2,3,(),&a));
|
||
|
|
assert!(w == PtrWrapper(2,3,(),&a) as PtrWrapper<[u8]>);
|
||
|
|
|
||
|
|
let w = coerce_triv_ptr_wrapper(TrivPtrWrapper(&a));
|
||
|
|
assert_eq!(&w.0, &a);
|
||
|
|
|
||
|
|
let z = coerce_fat_ptr_wrapper(PtrWrapper(2,3,(),&square_local));
|
||
|
|
assert_eq!((z.3)(6), 36);
|
||
|
|
}
|