index.pass.cpp
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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14
// <variant>
// template <class ...Types> class variant;
// constexpr size_t index() const noexcept;
#include <cassert>
#include <string>
#include <type_traits>
#include <variant>
#include "archetypes.h"
#include "test_macros.h"
#include "variant_test_helpers.h"
int main(int, char**) {
{
using V = std::variant<int, long>;
constexpr V v;
static_assert(v.index() == 0, "");
}
{
using V = std::variant<int, long>;
V v;
assert(v.index() == 0);
}
{
using V = std::variant<int, long>;
constexpr V v(std::in_place_index<1>);
static_assert(v.index() == 1, "");
}
{
using V = std::variant<int, std::string>;
V v("abc");
assert(v.index() == 1);
v = 42;
assert(v.index() == 0);
}
#ifndef TEST_HAS_NO_EXCEPTIONS
{
using V = std::variant<int, MakeEmptyT>;
V v;
assert(v.index() == 0);
makeEmpty(v);
assert(v.index() == std::variant_npos);
}
#endif
return 0;
}