libstdc++-v3/testsuite/25_algorithms/lexicographical_compare_three_way/constexpr.cc

   1 // Copyright (C) 2019-2024 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++20 } }
  19
  20 #include <algorithm>
  21
  22 constexpr bool
  23 test01(int i)
  24 {
  25   int a1[] = { 0, 1, 2, 3, 4, 5, 6, i, 8 };
  26   long a2[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
  27
  28   return std::lexicographical_compare_three_way(a1, a1+0, a2, a2+0) == 0
  29     && std::lexicographical_compare_three_way(a1, a1+9, a2, a2+9) == (i <=> 7)
  30     && std::lexicographical_compare_three_way(a1, a1+7, a2, a2+7) == 0
  31     && std::lexicographical_compare_three_way(a1, a1+8, a2, a2+7) > 0
  32     && std::lexicographical_compare_three_way(a1, a1+7, a2, a2+8) < 0;
  33 }
  34
  35 static_assert( test01(~7) );
  36 static_assert( test01(7) );
  37 static_assert( test01(8) );
  38
  39 constexpr bool
  40 test02(unsigned char i)
  41 {
  42   unsigned char a1[] = { 0, 1, 2, 3, 4, 5, 6, i, 8 };
  43   unsigned char a2[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
  44
  45   return std::lexicographical_compare_three_way(a1, a1+0, a2, a2+0) == 0
  46     && std::lexicographical_compare_three_way(a1, a1+9, a2, a2+9) == (i <=> 7)
  47     && std::lexicographical_compare_three_way(a1, a1+7, a2, a2+7) == 0
  48     && std::lexicographical_compare_three_way(a1, a1+8, a2, a2+7) > 0
  49     && std::lexicographical_compare_three_way(a1, a1+7, a2, a2+8) < 0;
  50 }
  51
  52 static_assert( test02(248) );
  53 static_assert( test02(7) );
  54 static_assert( test02(8) );
  55
  56 constexpr bool
  57 test03(unsigned char* p)
  58 {
  59   unsigned char a[2] = { 1, 2 };
  60   return std::lexicographical_compare_three_way(p, p, a, a+2) < 0
  61     && std::lexicographical_compare_three_way(a, a+2, p, p) > 0;
  62 }
  63
  64 static_assert( test03(nullptr) ); // ensure memcmp not called with nullptr