libcxx/test/std/ranges/range.factories/range.single.view/ctor.default.pass.cpp

   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
  11 // single_view() requires default_initializable<T> = default;
  12
  13 #include <ranges>
  14 #include <cassert>
  15
  16 #include "test_macros.h"
  17
  18 struct BigType { char buffer[64] = {10}; };
  19
  20 template<bool DefaultCtorEnabled>
  21 struct IsDefaultConstructible {
  22   IsDefaultConstructible() requires DefaultCtorEnabled = default;
  23 };
  24
  25 constexpr bool test() {
  26   static_assert( std::default_initializable<std::ranges::single_view<IsDefaultConstructible<true>>>);
  27   static_assert(!std::default_initializable<std::ranges::single_view<IsDefaultConstructible<false>>>);
  28
  29   {
  30     std::ranges::single_view<BigType> sv;
  31     assert(sv.data()->buffer[0] == 10);
  32     assert(sv.size() == 1);
  33   }
  34   {
  35     const std::ranges::single_view<BigType> sv;
  36     assert(sv.data()->buffer[0] == 10);
  37     assert(sv.size() == 1);
  38   }
  39
  40   return true;
  41 }
  42
  43 int main(int, char**) {
  44   test();
  45   static_assert(test());
  46
  47   return 0;
  48 }