libstdc++-v3/testsuite/26_numerics/lcm/1.cc

   1 // Copyright (C) 2015-2020 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-options "-std=gnu++17" }
  19 // { dg-do compile { target c++17 } }
  20
  21 #include <numeric>
  22
  23 #ifndef __cpp_lib_gcd_lcm
  24 # error "Feature-test macro for lcm missing"
  25 #elif __cpp_lib_gcd_lcm != 201606
  26 # error "Feature-test macro for lcm has wrong value"
  27 #endif
  28
  29 using std::lcm;
  30
  31 static_assert(lcm(21, 6) == 42, "");
  32 static_assert(lcm(41, 0) == 0, "LCD with zero is zero");
  33 static_assert(lcm(0, 7) == 0, "LCD with zero is zero");
  34 static_assert(lcm(0, 0) == 0, "no division by zero");
  35
  36 static_assert(lcm(1u, 2) == 2, "unsigned and signed");
  37 static_assert(lcm(3, 4u) == 12, "signed and unsigned");
  38 static_assert(lcm(5u, 6u) == 30, "unsigned and unsigned");
  39
  40 static_assert( std::is_same_v<decltype(lcm(1l, 1)), long> );
  41 static_assert( std::is_same_v<decltype(lcm(1ul, 1ull)), unsigned long long> );