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

   1 // Copyright (C) 2019-2023 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>
  24 #include <experimental/string_view>
  25
  26 template<typename T>
  27 constexpr bool
  28 rvalue_is_borrowed_range()
  29 {
  30   using std::ranges::borrowed_range;
  31
  32   // An lvalue range always models borrowed_range
  33   static_assert( borrowed_range<T&> );
  34   static_assert( borrowed_range<const T&> );
  35
  36   // Result should not depend on addition of const or rvalue-reference.
  37   static_assert( borrowed_range<T&&> == borrowed_range<T> );
  38   static_assert( borrowed_range<const T> == borrowed_range<T> );
  39   static_assert( borrowed_range<const T&&> == borrowed_range<T> );
  40
  41   return std::ranges::borrowed_range<T>;
  42 }
  43
  44 static_assert( rvalue_is_borrowed_range<std::ranges::subrange<int*, int*>>() );
  45 static_assert( rvalue_is_borrowed_range<std::ranges::empty_view<int>>() );
  46 static_assert( rvalue_is_borrowed_range<std::ranges::iota_view<int>>() );
  47 static_assert( rvalue_is_borrowed_range<std::ranges::iota_view<int, int>>() );
  48
  49 static_assert( rvalue_is_borrowed_range<std::span<int>>() );
  50 static_assert( rvalue_is_borrowed_range<std::span<int, 99>>() );
  51
  52 static_assert( ! rvalue_is_borrowed_range<std::string>() );
  53 static_assert( ! rvalue_is_borrowed_range<std::wstring>() );
  54
  55 static_assert( rvalue_is_borrowed_range<std::string_view>() );
  56 static_assert( rvalue_is_borrowed_range<std::wstring_view>() );
  57
  58 static_assert( rvalue_is_borrowed_range<std::experimental::string_view>() );
  59 static_assert( rvalue_is_borrowed_range<std::experimental::wstring_view>() );