| // -*- 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++98, c++03, c++11, c++14 |
| |
| // <variant> |
| |
| // template <class ...Types> class variant; |
| |
| #include <limits> |
| #include <type_traits> |
| #include <utility> |
| #include <variant> |
| |
| #include "test_macros.h" |
| |
| template <class Sequence> |
| struct make_variant_imp; |
| |
| template <size_t ...Indices> |
| struct make_variant_imp<std::integer_sequence<size_t, Indices...>> { |
| template <size_t> using AlwaysChar = char; |
| using type = std::variant<AlwaysChar<Indices>...>; |
| }; |
| |
| template <size_t N> |
| using make_variant_t = typename make_variant_imp<std::make_index_sequence<N>>::type; |
| |
| constexpr bool ExpectEqual = |
| #ifdef _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION |
| false; |
| #else |
| true; |
| #endif |
| |
| template <class IndexType> |
| void test_index_type() { |
| using Lim = std::numeric_limits<IndexType>; |
| using T1 = make_variant_t<Lim::max() - 1>; |
| using T2 = make_variant_t<Lim::max()>; |
| static_assert((sizeof(T1) == sizeof(T2)) == ExpectEqual, ""); |
| } |
| |
| template <class IndexType> |
| void test_index_internals() { |
| using Lim = std::numeric_limits<IndexType>; |
| static_assert(std::__choose_index_type(Lim::max() -1) != |
| std::__choose_index_type(Lim::max()), ""); |
| static_assert(std::is_same_v< |
| std::__variant_index_t<Lim::max()-1>, |
| std::__variant_index_t<Lim::max()> |
| > == ExpectEqual, ""); |
| using IndexT = std::__variant_index_t<Lim::max()-1>; |
| using IndexLim = std::numeric_limits<IndexT>; |
| static_assert(std::__variant_npos<IndexT> == IndexLim::max(), ""); |
| } |
| |
| int main(int, char**) { |
| test_index_type<unsigned char>(); |
| // This won't compile due to template depth issues. |
| //test_index_type<unsigned short>(); |
| test_index_internals<unsigned char>(); |
| test_index_internals<unsigned short>(); |
| |
| return 0; |
| } |