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// -*- 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.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <variant>
// template <size_t I, class T> struct variant_alternative; // undefined
// template <size_t I, class T> struct variant_alternative<I, const T>;
// template <size_t I, class T> struct variant_alternative<I, volatile T>;
// template <size_t I, class T> struct variant_alternative<I, const volatile T>;
// template <size_t I, class T>
// using variant_alternative_t = typename variant_alternative<I, T>::type;
//
// template <size_t I, class... Types>
// struct variant_alternative<I, variant<Types...>>;
#include <memory>
#include <type_traits>
#include <variant>
#include "test_macros.h"
#include "variant_test_helpers.hpp"
template <class V, size_t I, class E> void test() {
static_assert(
std::is_same_v<typename std::variant_alternative<I, V>::type, E>, "");
static_assert(
std::is_same_v<typename std::variant_alternative<I, const V>::type,
const E>,
"");
static_assert(
std::is_same_v<typename std::variant_alternative<I, volatile V>::type,
volatile E>,
"");
static_assert(
std::is_same_v<
typename std::variant_alternative<I, const volatile V>::type,
const volatile E>,
"");
static_assert(std::is_same_v<std::variant_alternative_t<I, V>, E>, "");
static_assert(std::is_same_v<std::variant_alternative_t<I, const V>, const E>,
"");
static_assert(
std::is_same_v<std::variant_alternative_t<I, volatile V>, volatile E>,
"");
static_assert(std::is_same_v<std::variant_alternative_t<I, const volatile V>,
const volatile E>,
"");
}
int main() {
{
using V = std::variant<int, void *, const void *, long double>;
test<V, 0, int>();
test<V, 1, void *>();
test<V, 2, const void *>();
test<V, 3, long double>();
}
#if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
{
using V = std::variant<int, int &, const int &, int &&, long double>;
test<V, 0, int>();
test<V, 1, int &>();
test<V, 2, const int &>();
test<V, 3, int &&>();
test<V, 4, long double>();
}
#endif
}
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