1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14, c++17 10 // UNSUPPORTED: libcpp-no-concepts 11 // UNSUPPORTED: gcc-10 12 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 13 14 // constexpr iterator<false> begin(); 15 // constexpr iterator<true> begin() const 16 // requires range<const V> && 17 // regular_invocable<const F&, range_reference_t<const V>>; 18 19 #include <ranges> 20 21 #include "test_macros.h" 22 #include "types.h" 23 24 template<class T> 25 concept BeginInvocable = requires(T t) { t.begin(); }; 26 27 constexpr bool test() { 28 int buff[8] = {0, 1, 2, 3, 4, 5, 6, 7}; 29 30 { 31 std::ranges::transform_view transformView(ContiguousView{buff}, Increment{}); 32 assert(transformView.begin().base() == buff); 33 assert(*transformView.begin() == 1); 34 } 35 36 { 37 std::ranges::transform_view transformView(ForwardView{buff}, Increment{}); 38 assert(transformView.begin().base().base() == buff); 39 assert(*transformView.begin() == 1); 40 } 41 42 { 43 std::ranges::transform_view transformView(InputView{buff}, Increment{}); 44 assert(transformView.begin().base().base() == buff); 45 assert(*transformView.begin() == 1); 46 } 47 48 { 49 const std::ranges::transform_view transformView(ContiguousView{buff}, IncrementConst{}); 50 assert(*transformView.begin() == 1); 51 } 52 53 static_assert(!BeginInvocable<const std::ranges::transform_view<ContiguousView, Increment>>); 54 55 return true; 56 } 57 58 int main(int, char**) { 59 test(); 60 static_assert(test()); 61 62 return 0; 63 } 64