libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc

   1 // { dg-options "-std=gnu++17" }
   2 // { dg-do compile { target c++17 } }
   3
   4 // Copyright (C) 2017-2019 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <string>
  22
  23 template<typename CT>
  24   constexpr bool
  25   test_assign()
  26   {
  27     using char_type = typename CT::char_type;
  28     char_type s1[2] = {};
  29     const char_type s2[2] = {1, 0};
  30     CT::assign(s1[0], s2[0]);
  31     return s1[0] == char_type{1};
  32   }
  33
  34 template<typename CT>
  35   constexpr bool
  36   test_compare()
  37   {
  38     using char_type = typename CT::char_type;
  39     const char_type s1[3] = {1, 2, 3};
  40     const char_type s2[3] = {1, 2, 3};
  41     if (CT::compare(s1, s2, 3) != 0)
  42       return false;
  43     if (CT::compare(s2, s1, 3) != 0)
  44       return false;
  45     if (CT::compare(s1+1, s2, 2) <= 0)
  46       return false;
  47     return true;
  48   }
  49
  50 template<typename CT>
  51   constexpr bool
  52   test_length()
  53   {
  54     using char_type = typename CT::char_type;
  55     const char_type s1[4] = {1, 2, 3, 0};
  56     if (CT::length(s1) != 3)
  57       return false;
  58     if (CT::length(s1+1) != 2)
  59       return false;
  60     return true;
  61   }
  62
  63 template<typename CT>
  64   constexpr bool
  65   test_find()
  66   {
  67     using char_type = typename CT::char_type;
  68     const char_type s1[3] = {1, 2, 3};
  69     if (CT::find(s1, 3, char_type{2}) != s1+1)
  70       return false;
  71     if (CT::find(s1, 3, char_type{4}) != nullptr)
  72       return false;
  73     return true;
  74   }
  75
  76 #ifndef __cpp_lib_constexpr_char_traits
  77 # error Feature-test macro for constexpr char_traits is missing
  78 #elif __cpp_lib_constexpr_char_traits != 201611
  79 # error Feature-test macro for constexpr char_traits has the wrong value
  80 #endif
  81
  82 static_assert( test_assign<std::char_traits<char>>() );
  83 static_assert( test_compare<std::char_traits<char>>() );
  84 static_assert( test_length<std::char_traits<char>>() );
  85 static_assert( test_find<std::char_traits<char>>() );
  86 #ifdef _GLIBCXX_USE_WCHAR_T
  87 static_assert( test_assign<std::char_traits<wchar_t>>() );
  88 static_assert( test_compare<std::char_traits<wchar_t>>() );
  89 static_assert( test_length<std::char_traits<wchar_t>>() );
  90 static_assert( test_find<std::char_traits<wchar_t>>() );
  91 #endif
  92 static_assert( test_assign<std::char_traits<char16_t>>() );
  93 static_assert( test_compare<std::char_traits<char16_t>>() );
  94 static_assert( test_length<std::char_traits<char16_t>>() );
  95 static_assert( test_find<std::char_traits<char16_t>>() );
  96 static_assert( test_assign<std::char_traits<char32_t>>() );
  97 static_assert( test_compare<std::char_traits<char32_t>>() );
  98 static_assert( test_length<std::char_traits<char32_t>>() );
  99 static_assert( test_find<std::char_traits<char32_t>>() );
 100
 101 struct C { unsigned char c; };
 102 constexpr bool operator==(const C& c1, const C& c2) { return c1.c == c2.c; }
 103 constexpr bool operator<(const C& c1, const C& c2) { return c1.c < c2.c; }
 104 static_assert( test_assign<std::char_traits<C>>() );
 105 static_assert( test_compare<std::char_traits<C>>() );
 106 static_assert( test_length<std::char_traits<C>>() );
 107 static_assert( test_find<std::char_traits<C>>() );