Eric Fiselier 9c09757bca [libc++] Revert switch-based std::variant implementation again.
These changes cause substantial binary size increases for non-opt builds.
For example, the visit.pass.cpp test grows from 20k to 420k.

Further work will be done to re-land this patch without the size increases,
but that work is proving too tricky to fix forward.

This patch fully reverts:

* 35d226911165a9aae1f01f521a0019f1a9c0a25f

And it partially reverts:

* bb43a0cd4adc4f1fa12e0d2fd1fe9aa6b5c00e34

The latter of which added XFAIL's to new variant tests
because the new implementation needlessly makes non-throwing code
paths in variant invoke throwing code.

This means the reverted change also breaks source backwards compat
with code compiled on OS X targeting older system dylibs. There is no
need for this to be the case. We should fix it before recommitting.

Reviewed as:
https://reviews.llvm.org/D91662
2020-11-17 23:09:31 -05:00

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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;
}