libstdc++-v3/testsuite/std/ranges/view.cc

   1 // Copyright (C) 2019-2021 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do compile { target c++2a } }
  20
  21 #include <ranges>
  22 #include <span>
  23 #include <string_view>
  24 #include <experimental/string_view>
  25 #include <vector>
  26 #include <vector>
  27 #include <set>
  28 #include <unordered_set>
  29 #include <regex>
  30 #include <testsuite_iterators.h>
  31
  32 static_assert(std::ranges::view<std::span<int>>);
  33 static_assert(std::ranges::view<std::span<int, 0>>);
  34 static_assert(!std::ranges::view<std::span<int, 1>>);
  35 static_assert(std::ranges::view<std::string_view>);
  36 static_assert(std::ranges::view<std::experimental::string_view>);
  37
  38 static_assert(!std::ranges::view<std::vector<int>>);
  39 static_assert(!std::ranges::view<const std::vector<int>>);
  40 static_assert(!std::ranges::view<std::initializer_list<int>>);
  41 static_assert(!std::ranges::view<const std::initializer_list<int>>);
  42 static_assert(!std::ranges::view<std::set<int>>);
  43 static_assert(!std::ranges::view<const std::set<int>>);
  44 static_assert(!std::ranges::view<std::multiset<int>>);
  45 static_assert(!std::ranges::view<std::unordered_set<int>>);
  46 static_assert(!std::ranges::view<std::unordered_multiset<int>>);
  47 static_assert(!std::ranges::view<std::cmatch>);
  48
  49 // const test_random_access_range<T> is not a range:
  50 static_assert(!std::ranges::view<__gnu_test::test_random_access_range<int>>);
  51
  52 template<typename T>
  53 struct test_view
  54 : __gnu_test::test_random_access_range<T>, std::ranges::view_base
  55 {
  56   // views must be default-initializable:
  57   test_view() : __gnu_test::test_random_access_range<T>(nullptr, nullptr) { }
  58 };
  59
  60 static_assert(std::ranges::view<test_view<int>>);
  61
  62 template<>
  63 constexpr bool std::ranges::enable_view<test_view<long>> = false;
  64
  65 static_assert(!std::ranges::view<test_view<long>>);