File: as_const.pass.cpp

package info (click to toggle)
llvm-toolchain-7 1%3A7.0.1-8~deb9u3
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 733,456 kB
  • sloc: cpp: 3,776,651; ansic: 633,271; asm: 350,301; python: 142,716; objc: 107,612; sh: 22,626; lisp: 11,056; perl: 7,999; pascal: 6,742; ml: 5,537; awk: 3,536; makefile: 2,557; cs: 2,027; xml: 841; ruby: 156
file content (46 lines) | stat: -rw-r--r-- 1,811 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++98, c++03, c++11, c++14

// template <class T> constexpr add_const<T>& as_const(T& t) noexcept;      // C++17
// template <class T>           add_const<T>& as_const(const T&&) = delete; // C++17

#include <utility>
#include <cassert>

struct S {int i;};
bool operator==(const S& x, const S& y) { return x.i == y.i; }
bool operator==(const volatile S& x, const volatile S& y) { return x.i == y.i; }

template<typename T>
void test(T& t)
{
    static_assert(std::is_const<typename std::remove_reference<decltype(std::as_const                  (t))>::type>::value, "");
    static_assert(std::is_const<typename std::remove_reference<decltype(std::as_const<               T>(t))>::type>::value, "");
    static_assert(std::is_const<typename std::remove_reference<decltype(std::as_const<const          T>(t))>::type>::value, "");
    static_assert(std::is_const<typename std::remove_reference<decltype(std::as_const<volatile       T>(t))>::type>::value, "");
    static_assert(std::is_const<typename std::remove_reference<decltype(std::as_const<const volatile T>(t))>::type>::value, "");

    assert(std::as_const(t) == t);
    assert(std::as_const<               T>(t) == t);
    assert(std::as_const<const          T>(t) == t);
    assert(std::as_const<volatile       T>(t) == t);
    assert(std::as_const<const volatile T>(t) == t);
}

int main()
{
    int i = 3;
    double d = 4.0;
    S s{2};
    test(i);
    test(d);
    test(s);
}