libstdc++-v3/testsuite/std/text_encoding/requirements.cc

   1 // { dg-do compile { target c++26 } }
   2 // { dg-add-options no_pch }
   3
   4 #include <text_encoding>
   5 #ifndef __cpp_lib_text_encoding
   6 # error "Feature-test macro for text_encoding missing in <text_encoding>"
   7 #elif __cpp_lib_text_encoding != 202306L
   8 # error "Feature-test macro for text_encoding has wrong value in <text_encoding>"
   9 #endif
  10
  11 #undef __cpp_lib_expected
  12 #include <version>
  13 #ifndef __cpp_lib_text_encoding
  14 # error "Feature-test macro for text_encoding missing in <version>"
  15 #elif __cpp_lib_text_encoding != 202306L
  16 # error "Feature-test macro for text_encoding has wrong value in <version>"
  17 #endif
  18
  19 #include <concepts>
  20 #include <ranges>
  21 static_assert( std::is_trivially_copyable_v<std::text_encoding> );
  22
  23 using aliases_view = std::text_encoding::aliases_view;
  24 static_assert( std::copyable<aliases_view> );
  25 static_assert( std::ranges::view<aliases_view> );
  26 static_assert( std::ranges::random_access_range<aliases_view> );
  27 static_assert( std::ranges::borrowed_range<aliases_view> );
  28 static_assert( std::same_as<std::ranges::range_value_t<aliases_view>,
  29                             const char*> );
  30 static_assert( std::same_as<std::ranges::range_reference_t<aliases_view>,
  31                             const char*> );
  32
  33 #include <testsuite_hooks.h>
  34
  35 constexpr bool
  36 test_constexpr_iterator()
  37 {
  38   // This encoding has two aliases, "UTF-8" and "csUTF8".
  39   const auto a = std::text_encoding(std::text_encoding::UTF8).aliases();
  40   const auto begin = a.begin();
  41   const auto end = a.end();
  42   auto iter = begin;
  43   VERIFY( *iter == *begin );
  44   VERIFY( *iter == iter[0] );
  45   VERIFY( iter[1] == begin[1] );
  46   --++iter;
  47   VERIFY( iter == begin );
  48   auto iter2 = iter++;
  49   VERIFY( iter2 == begin );
  50   VERIFY( iter != begin );
  51   iter2 = iter--;
  52   VERIFY( iter2 != begin );
  53   VERIFY( iter == begin );
  54   iter++++; // Increments prvalue returned by operator++(int) instead of iter.
  55   VERIFY( iter == iter2 );
  56   iter----; // Decrements prvalue returned by operator++(int) instead of iter.
  57   VERIFY( iter == begin );
  58   const auto d = std::ranges::distance(a);
  59   iter += d;
  60   VERIFY( iter == end );
  61   VERIFY( (iter - begin) == d );
  62   VERIFY( (begin + 2) == iter );
  63   VERIFY( (2 + begin) == iter );
  64   VERIFY( iter[-1] == begin[1] );
  65   iter -= d;
  66   VERIFY( iter == begin );
  67   VERIFY( *(iter + 1) == iter[1] );
  68   VERIFY( (1 + iter - 1) == begin );
  69   VERIFY( (-1 + (iter - -2) + -1) == begin );
  70
  71   std::ranges::iterator_t<std::text_encoding::aliases_view> singular{};
  72   VERIFY( (singular + 0) == singular );
  73   VERIFY( (singular - 0) == singular );
  74
  75   return true;
  76 }
  77 static_assert( test_constexpr_iterator() );