libstdc++-v3/testsuite/experimental/optional/constexpr/relops/1.cc

   1 // { dg-do compile { target c++14 } }
   2
   3 // Copyright (C) 2013-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 #include <experimental/optional>
  21 #include <testsuite_hooks.h>
  22
  23 namespace ns
  24 {
  25   struct value_type
  26   {
  27     int i;
  28     const char* s;
  29   };
  30
  31   constexpr bool
  32   strcmp(const char* lhs, const char* rhs)
  33   {
  34     return *lhs == *rhs && (!*lhs || strcmp(lhs + 1, rhs + 1));
  35   }
  36
  37   constexpr bool
  38   strrel(const char* lhs, const char* rhs)
  39   {
  40     return (*rhs && (!*lhs || (*lhs < *rhs)))
  41       || ((*lhs && *rhs && !(*rhs < *lhs)) && strrel(lhs + 1, rhs + 1));
  42   }
  43
  44   constexpr bool
  45   operator==(value_type const& lhs, value_type const& rhs)
  46   { return (lhs.i == rhs.i) && strcmp(lhs.s, rhs.s); }
  47
  48   constexpr bool
  49   operator!=(value_type const& lhs, value_type const& rhs)
  50   { return !(lhs == rhs); }
  51
  52   constexpr bool
  53   operator<(value_type const& lhs, value_type const& rhs)
  54   { return (lhs.i < rhs.i) || (!(rhs.i < lhs.i) && strrel(lhs.s, rhs.s)); }
  55
  56 } // namespace ns
  57
  58 int main()
  59 {
  60   using ns::value_type;
  61   using O = std::experimental::optional<value_type>;
  62
  63   {
  64     constexpr O o, p;
  65     static_assert( o == p, "" );
  66     static_assert( !(o != p), "" );
  67   }
  68
  69   {
  70     constexpr O o { value_type { 42, "forty-two" } }, p;
  71     static_assert( !(o == p), "" );
  72     static_assert( o != p, "" );
  73   }
  74
  75   {
  76     constexpr O o, p { value_type { 42, "forty-two" } };
  77     static_assert( !(o == p), "" );
  78     static_assert( o != p, "" );
  79   }
  80
  81   {
  82     constexpr O o { value_type { 11, "eleventy" } }, p { value_type { 42, "forty-two" } };
  83     static_assert( !(o == p), "" );
  84     static_assert( o != p, "" );
  85   }
  86
  87   {
  88     constexpr O o { value_type { 42, "forty-two" } }, p { value_type { 11, "eleventy" } };
  89     static_assert( !(o == p), "" );
  90     static_assert( o != p, "" );
  91   }
  92
  93   {
  94     constexpr O o { value_type { 42, "forty-two" } }, p { value_type { 42, "forty-two" } };
  95     static_assert( o == p, "" );
  96     static_assert( !(o != p), "" );
  97   }
  98 }