llvm/libcxx/test/std/utilities/meta/meta.trans/meta.trans.ptr/add_pointer.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// type_traits

// add_pointer
// If T names a referenceable type or a (possibly cv-qualified) void type then
//    the member typedef type shall name the same type as remove_reference_t<T>*;
//    otherwise, type shall name T.

#include <type_traits>
#include "test_macros.h"

template <class T, class U>
void test_add_pointer()
{
    ASSERT_SAME_TYPE(U, typename std::add_pointer<T>::type);
#if TEST_STD_VER > 11
    ASSERT_SAME_TYPE(U, std::add_pointer_t<T>);
#endif
}

template <class F>
void test_function0()
{
    ASSERT_SAME_TYPE(F*, typename std::add_pointer<F>::type);
#if TEST_STD_VER > 11
    ASSERT_SAME_TYPE(F*, std::add_pointer_t<F>);
#endif
}

template <class F>
void test_function1()
{
    ASSERT_SAME_TYPE(F, typename std::add_pointer<F>::type);
#if TEST_STD_VER > 11
    ASSERT_SAME_TYPE(F, std::add_pointer_t<F>);
#endif
}

struct Foo {};

int main(int, char**)
{
    test_add_pointer<void, void*>();
    test_add_pointer<int, int*>();
    test_add_pointer<int[3], int(*)[3]>();
    test_add_pointer<int&, int*>();
    test_add_pointer<const int&, const int*>();
    test_add_pointer<int*, int**>();
    test_add_pointer<const int*, const int**>();
    test_add_pointer<Foo, Foo*>();

//  LWG 2101 specifically talks about add_pointer and functions.
//  The term of art is "a referenceable type", which a cv- or ref-qualified function is not.
    test_function0<void()>();
#if TEST_STD_VER >= 11
    test_function1<void() const>();
    test_function1<void() &>();
    test_function1<void() &&>();
    test_function1<void() const &>();
    test_function1<void() const &&>();
#endif

//  But a cv- or ref-qualified member function *is* "a referenceable type"
    test_function0<void (Foo::*)()>();
#if TEST_STD_VER >= 11
    test_function0<void (Foo::*)() const>();
    test_function0<void (Foo::*)() &>();
    test_function0<void (Foo::*)() &&>();
    test_function0<void (Foo::*)() const &>();
    test_function0<void (Foo::*)() const &&>();
#endif

  return 0;
}