//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// <tuple>
// template<class... Types>
// tuple<Types&&...> forward_as_tuple(Types&&... t);
// UNSUPPORTED: c++03
#include <tuple>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
template <class Tuple>
void
test0(const Tuple&)
{
static_assert(std::tuple_size<Tuple>::value == 0, "");
}
template <class Tuple>
void
test1a(const Tuple& t)
{
static_assert(std::tuple_size<Tuple>::value == 1, "");
static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, int&&>::value, "");
assert(std::get<0>(t) == 1);
}
template <class Tuple>
void
test1b(const Tuple& t)
{
static_assert(std::tuple_size<Tuple>::value == 1, "");
static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, int&>::value, "");
assert(std::get<0>(t) == 2);
}
template <class Tuple>
void
test2a(const Tuple& t)
{
static_assert(std::tuple_size<Tuple>::value == 2, "");
static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, double&>::value, "");
static_assert(std::is_same<typename std::tuple_element<1, Tuple>::type, char&>::value, "");
assert(std::get<0>(t) == 2.5);
assert(std::get<1>(t) == 'a');
}
#if TEST_STD_VER > 11
template <class Tuple>
constexpr int
test3(const Tuple&)
{
return std::tuple_size<Tuple>::value;
}
#endif
int main(int, char**)
{
{
test0(std::forward_as_tuple());
}
{
test1a(std::forward_as_tuple(1));
}
{
int i = 2;
test1b(std::forward_as_tuple(i));
}
{
double i = 2.5;
char c = 'a';
test2a(std::forward_as_tuple(i, c));
#if TEST_STD_VER > 11
static_assert ( test3 (std::forward_as_tuple(i, c)) == 2, "" );
#endif
}
return 0;
}