// 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. // FIXME: investigate again once #296 is fixed // compile-flags: -Zmir-emit-validate=0 #![feature(coerce_unsized, unsize)] use std::ops::CoerceUnsized; use std::marker::Unsize; fn identity_coercion(x: &(Fn(u32)->u32 + Send)) -> &Fn(u32)->u32 { x } fn fn_coercions(f: &fn(u32) -> u32) -> (unsafe fn(u32) -> u32, &(Fn(u32) -> u32+Send)) { (*f, f) } 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: ?Sized> CoerceUnsized> for PtrWrapper<'a, T> {} struct TrivPtrWrapper<'a, T: 'a+?Sized>(&'a T); impl<'a, T: ?Sized+Unsize, U: ?Sized> CoerceUnsized> for TrivPtrWrapper<'a, T> {} fn coerce_ptr_wrapper(p: PtrWrapper<[u8; 3]>) -> PtrWrapper<[u8]> { p } fn coerce_triv_ptr_wrapper(p: TrivPtrWrapper<[u8; 3]>) -> TrivPtrWrapper<[u8]> { p } fn coerce_fat_ptr_wrapper(p: PtrWrapper u32+Send>) -> PtrWrapper u32> { p } fn coerce_ptr_wrapper_poly<'a, T, Trait: ?Sized>(p: PtrWrapper<'a, T>) -> PtrWrapper<'a, Trait> where PtrWrapper<'a, T>: CoerceUnsized> { 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 *const (), square as *const()); 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); let z: PtrWrapper u32> = coerce_ptr_wrapper_poly(PtrWrapper(2,3,(),&square_local)); assert_eq!((z.3)(6), 36); }