1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // test forward
11
12 #include <utility>
13 #include <cassert>
14
15 #include "test_macros.h"
16
17 struct A
18 {
19 };
20
source()21 A source() {return A();}
csource()22 const A csource() {return A();}
23
24 typedef char one;
25 struct two {one _[2];};
26 struct four {one _[4];};
27 struct eight {one _[8];};
28
29 one test(A&);
30 two test(const A&);
31
main()32 int main()
33 {
34 A a;
35 const A ca = A();
36
37 ((void)a); // Prevent unused warning
38 ((void)ca); // Prevent unused warning
39
40 #if TEST_STD_VER < 11
41 static_assert(sizeof(test(std::forward<A&>(a))) == 1, "");
42 static_assert(sizeof(test(std::forward<A>(a))) == 1, "");
43
44 // Libc++'s C++03 implementation of 'forward' cannot accept true non-const
45 // rvalues.
46 // static_assert(sizeof(test(std::forward<A>(source()))) == 2, "");
47
48 static_assert(sizeof(test(std::forward<const A&>(a))) == 2, "");
49 static_assert(sizeof(test(std::forward<const A&>(source()))) == 2, "");
50 static_assert(sizeof(test(std::forward<const A>(a))) == 2, "");
51 static_assert(sizeof(test(std::forward<const A>(source()))) == 2, "");
52
53 static_assert(sizeof(test(std::forward<const A&>(ca))) == 2, "");
54 static_assert(sizeof(test(std::forward<const A&>(csource()))) == 2, "");
55 static_assert(sizeof(test(std::forward<const A>(ca))) == 2, "");
56 static_assert(sizeof(test(std::forward<const A>(csource()))) == 2, "");
57 #endif
58 }
59