libstdc++-v3/testsuite/experimental/string_view/operations/compare/char/70483.cc

   1 // Copyright (C) 2017-2020 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-do compile { target c++14 } }
  19
  20 #include <experimental/string_view>
  21
  22 struct constexpr_char_traits : std::char_traits<char>
  23 {
  24   static constexpr size_t
  25   length(const char* val)
  26   {
  27     size_t res = 0;
  28     for (; val[res] != '\0'; ++res)
  29       ;
  30     return res;
  31   }
  32
  33   static constexpr int
  34   compare(const char* lhs, const char* rhs, std::size_t count)
  35   {
  36     for (size_t pos = 0; pos < count; ++pos)
  37     {
  38       if (lhs[pos] != rhs[pos])
  39         return lhs[pos] - rhs[pos];
  40     }
  41     return 0;
  42   }
  43
  44   static constexpr const char*
  45   find(const char* p, std::size_t n, char c)
  46   {
  47     for (size_t pos = 0; pos < n; ++pos)
  48       if (p[pos] == c)
  49         return p + pos;
  50     return nullptr;
  51   }
  52 };
  53
  54 using string_view
  55   = std::experimental::basic_string_view<char, constexpr_char_traits>;
  56
  57 constexpr
  58 string_view get()
  59 {
  60     string_view res = "x::";
  61     string_view start_pattern = "x";
  62     res = res.substr(res.find(start_pattern) + start_pattern.size());
  63     res = res.substr(0, res.find_first_of(";]"));
  64     res = res.substr(res.rfind("::"));
  65     return res;
  66 }
  67
  68 static_assert( get() == get() );