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//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
// <tuple>
// template<class... Types>
// tuple<Types&&...> forward_as_tuple(Types&&... t);
// UNSUPPORTED: c++98, c++03
#include <tuple>
#include <type_traits>
#include <cassert>
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 _LIBCPP_STD_VER > 11
template <class Tuple>
constexpr int
test3(const Tuple&)
{
return std::tuple_size<Tuple>::value;
}
#endif
int main()
{
{
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 _LIBCPP_STD_VER > 11
static_assert ( test3 (std::forward_as_tuple(i, c)) == 2, "" );
#endif
}
}
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