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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
// XFAIL: with_system_cxx_lib=macosx10.12
// XFAIL: with_system_cxx_lib=macosx10.11
// XFAIL: with_system_cxx_lib=macosx10.10
// XFAIL: with_system_cxx_lib=macosx10.9
// XFAIL: with_system_cxx_lib=macosx10.7
// XFAIL: with_system_cxx_lib=macosx10.8
// <variant>
// template <class ...Types> class variant;
// template <size_t I, class U, class ...Args>
// variant_alternative_t<I, variant<Types...>>& emplace(initializer_list<U> il,Args&&... args);
#include <cassert>
#include <string>
#include <type_traits>
#include <variant>
#include "archetypes.hpp"
#include "test_convertible.hpp"
#include "test_macros.h"
struct InitList {
std::size_t size;
constexpr InitList(std::initializer_list<int> il) : size(il.size()) {}
};
struct InitListArg {
std::size_t size;
int value;
constexpr InitListArg(std::initializer_list<int> il, int v)
: size(il.size()), value(v) {}
};
template <class Var, size_t I, class... Args>
constexpr auto test_emplace_exists_imp(int) -> decltype(
std::declval<Var>().template emplace<I>(std::declval<Args>()...), true) {
return true;
}
template <class, size_t, class...>
constexpr auto test_emplace_exists_imp(long) -> bool {
return false;
}
template <class Var, size_t I, class... Args> constexpr bool emplace_exists() {
return test_emplace_exists_imp<Var, I, Args...>(0);
}
void test_emplace_sfinae() {
using V =
std::variant<int, TestTypes::NoCtors, InitList, InitListArg, long, long>;
using IL = std::initializer_list<int>;
static_assert(!emplace_exists<V, 1, IL>(), "no such constructor");
static_assert(emplace_exists<V, 2, IL>(), "");
static_assert(!emplace_exists<V, 2, int>(), "args don't match");
static_assert(!emplace_exists<V, 2, IL, int>(), "too many args");
static_assert(emplace_exists<V, 3, IL, int>(), "");
static_assert(!emplace_exists<V, 3, int>(), "args don't match");
static_assert(!emplace_exists<V, 3, IL>(), "too few args");
static_assert(!emplace_exists<V, 3, IL, int, int>(), "too many args");
}
void test_basic() {
using V = std::variant<int, InitList, InitListArg, TestTypes::NoCtors>;
V v;
auto& ref1 = v.emplace<1>({1, 2, 3});
static_assert(std::is_same_v<InitList&, decltype(ref1)>, "");
assert(std::get<1>(v).size == 3);
assert(&ref1 == &std::get<1>(v));
auto& ref2 = v.emplace<2>({1, 2, 3, 4}, 42);
static_assert(std::is_same_v<InitListArg&, decltype(ref2)>, "");
assert(std::get<2>(v).size == 4);
assert(std::get<2>(v).value == 42);
assert(&ref2 == &std::get<2>(v));
auto& ref3 = v.emplace<1>({1});
static_assert(std::is_same_v<InitList&, decltype(ref3)>, "");
assert(std::get<1>(v).size == 1);
assert(&ref3 == &std::get<1>(v));
}
int main() {
test_basic();
test_emplace_sfinae();
}
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