xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.elements/iterator/base.pass.cpp (revision 67c4033358f39adcba53e9b70bdd4799c5a306ac)
194461822SHui Xie //===----------------------------------------------------------------------===//
294461822SHui Xie //
394461822SHui Xie // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
494461822SHui Xie // See https://llvm.org/LICENSE.txt for license information.
594461822SHui Xie // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
694461822SHui Xie //
794461822SHui Xie //===----------------------------------------------------------------------===//
894461822SHui Xie 
994461822SHui Xie // UNSUPPORTED: c++03, c++11, c++14, c++17
1094461822SHui Xie 
1194461822SHui Xie // constexpr const iterator_t<Base>& base() const & noexcept;
1294461822SHui Xie // constexpr iterator_t<Base> base() &&;
1394461822SHui Xie 
1494461822SHui Xie #include <cassert>
1594461822SHui Xie #include <ranges>
1694461822SHui Xie #include <tuple>
1794461822SHui Xie #include <type_traits>
1894461822SHui Xie #include <utility>
1994461822SHui Xie 
2094461822SHui Xie #include "MoveOnly.h"
2194461822SHui Xie #include "../types.h"
2294461822SHui Xie 
2394461822SHui Xie // Test Noexcept
2494461822SHui Xie template <class T>
2594461822SHui Xie concept IsBaseNoexcept =
2694461822SHui Xie     requires {
2794461822SHui Xie       { std::declval<T>().base() } noexcept;
2894461822SHui Xie     };
2994461822SHui Xie 
3094461822SHui Xie using BaseView     = std::ranges::subrange<std::tuple<int>*>;
3194461822SHui Xie using ElementsIter = std::ranges::iterator_t<std::ranges::elements_view<BaseView, 0>>;
3294461822SHui Xie 
3394461822SHui Xie static_assert(IsBaseNoexcept<const ElementsIter&>);
3494461822SHui Xie static_assert(IsBaseNoexcept<ElementsIter&>);
3594461822SHui Xie static_assert(IsBaseNoexcept<const ElementsIter&&>);
36*67c40333SStephan T. Lavavej LIBCPP_STATIC_ASSERT(!IsBaseNoexcept<ElementsIter&&>);
3794461822SHui Xie 
test()3894461822SHui Xie constexpr bool test() {
3994461822SHui Xie   std::tuple<int> t{5};
4094461822SHui Xie 
4194461822SHui Xie   // const &
4294461822SHui Xie   {
4394461822SHui Xie     const ElementsIter it{&t};
4494461822SHui Xie     decltype(auto) base = it.base();
4594461822SHui Xie     static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
4694461822SHui Xie     assert(base == &t);
4794461822SHui Xie   }
4894461822SHui Xie 
4994461822SHui Xie   // &
5094461822SHui Xie   {
5194461822SHui Xie     ElementsIter it{&t};
5294461822SHui Xie     decltype(auto) base = it.base();
5394461822SHui Xie     static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
5494461822SHui Xie     assert(base == &t);
5594461822SHui Xie   }
5694461822SHui Xie 
5794461822SHui Xie   // &&
5894461822SHui Xie   {
5994461822SHui Xie     ElementsIter it{&t};
6094461822SHui Xie     decltype(auto) base = std::move(it).base();
6194461822SHui Xie     static_assert(std::is_same_v<decltype(base), std::tuple<int>*>);
6294461822SHui Xie     assert(base == &t);
6394461822SHui Xie   }
6494461822SHui Xie 
6594461822SHui Xie   // const &&
6694461822SHui Xie   {
6794461822SHui Xie     const ElementsIter it{&t};
6894461822SHui Xie     decltype(auto) base = std::move(it).base();
6994461822SHui Xie     static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
7094461822SHui Xie     assert(base == &t);
7194461822SHui Xie   }
7294461822SHui Xie 
7394461822SHui Xie   // move only
7494461822SHui Xie   {
7594461822SHui Xie     struct MoveOnlyIter : IterBase<MoveOnlyIter> {
7694461822SHui Xie       MoveOnly mo;
7794461822SHui Xie     };
7894461822SHui Xie     struct Sent {
7994461822SHui Xie       constexpr bool operator==(const MoveOnlyIter&) const { return true; }
8094461822SHui Xie     };
8194461822SHui Xie 
8294461822SHui Xie     using MoveOnlyElemIter =
8394461822SHui Xie         std::ranges::iterator_t<std::ranges::elements_view<std::ranges::subrange<MoveOnlyIter, Sent>, 0>>;
8494461822SHui Xie 
8594461822SHui Xie     MoveOnlyElemIter it{MoveOnlyIter{{}, MoveOnly{5}}};
8694461822SHui Xie     decltype(auto) base = std::move(it).base();
8794461822SHui Xie     static_assert(std::is_same_v<decltype(base), MoveOnlyIter>);
8894461822SHui Xie     assert(base.mo.get() == 5);
8994461822SHui Xie   }
9094461822SHui Xie 
9194461822SHui Xie   return true;
9294461822SHui Xie }
9394461822SHui Xie 
main(int,char **)9494461822SHui Xie int main(int, char**) {
9594461822SHui Xie   test();
9694461822SHui Xie   static_assert(test());
9794461822SHui Xie   return 0;
9894461822SHui Xie }
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