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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 <class ...Types> class variant;
// template <class T> constexpr variant(T&&) noexcept(see below);
#include <cassert>
#include <string>
#include <type_traits>
#include <variant>
#include "test_convertible.hpp"
#include "test_macros.h"
#include "variant_test_helpers.hpp"
struct Dummy {
Dummy() = default;
};
struct ThrowsT {
ThrowsT(int) noexcept(false) {}
};
struct NoThrowT {
NoThrowT(int) noexcept(true) {}
};
struct AnyConstructible { template <typename T> AnyConstructible(T&&) {} };
struct NoConstructible { NoConstructible() = delete; };
void test_T_ctor_noexcept() {
{
using V = std::variant<Dummy, NoThrowT>;
static_assert(std::is_nothrow_constructible<V, int>::value, "");
}
{
using V = std::variant<Dummy, ThrowsT>;
static_assert(!std::is_nothrow_constructible<V, int>::value, "");
}
}
void test_T_ctor_sfinae() {
{
using V = std::variant<long, unsigned>;
static_assert(!std::is_constructible<V, int>::value, "ambiguous");
}
{
using V = std::variant<std::string, std::string>;
static_assert(!std::is_constructible<V, const char *>::value, "ambiguous");
}
{
using V = std::variant<std::string, void *>;
static_assert(!std::is_constructible<V, int>::value,
"no matching constructor");
}
{
using V = std::variant<AnyConstructible, NoConstructible>;
static_assert(
!std::is_constructible<V, std::in_place_type_t<NoConstructible>>::value,
"no matching constructor");
static_assert(!std::is_constructible<V, std::in_place_index_t<1>>::value,
"no matching constructor");
}
#if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
{
using V = std::variant<int, int &&>;
static_assert(!std::is_constructible<V, int>::value, "ambiguous");
}
{
using V = std::variant<int, const int &>;
static_assert(!std::is_constructible<V, int>::value, "ambiguous");
}
#endif
}
void test_T_ctor_basic() {
{
constexpr std::variant<int> v(42);
static_assert(v.index() == 0, "");
static_assert(std::get<0>(v) == 42, "");
}
{
constexpr std::variant<int, long> v(42l);
static_assert(v.index() == 1, "");
static_assert(std::get<1>(v) == 42, "");
}
#if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
{
using V = std::variant<const int &, int &&, long>;
static_assert(std::is_convertible<int &, V>::value, "must be implicit");
int x = 42;
V v(x);
assert(v.index() == 0);
assert(&std::get<0>(v) == &x);
}
{
using V = std::variant<const int &, int &&, long>;
static_assert(std::is_convertible<int, V>::value, "must be implicit");
int x = 42;
V v(std::move(x));
assert(v.index() == 1);
assert(&std::get<1>(v) == &x);
}
#endif
}
int main() {
test_T_ctor_basic();
test_T_ctor_noexcept();
test_T_ctor_sfinae();
}
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