You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
libcxx/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp

51 lines
2.1 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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> class tuple;
// template <class... Types>
// class tuple_size<tuple<Types...>>
// : public integral_constant<size_t, sizeof...(Types)> { };
//
// LWG #2212 says that tuple_size and tuple_element must be
// available after including <utility>
#include <cstddef>
#include <utility>
#include <type_traits>
template <class T, std::size_t N, class U, size_t idx>
void test()
{
static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
std::tuple_size<T> >::value), "");
static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
std::tuple_size<const T> >::value), "");
static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
std::tuple_size<volatile T> >::value), "");
static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
std::tuple_size<const volatile T> >::value), "");
static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
}
int main()
{
test<std::pair<int, int>, 2, int, 0>();
test<std::pair<int, int>, 2, int, 1>();
test<std::pair<const int, int>, 2, int, 1>();
test<std::pair<int, volatile int>, 2, volatile int, 1>();
test<std::pair<char *, int>, 2, char *, 0>();
test<std::pair<char *, int>, 2, int, 1>();
}