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

   1 // Copyright (C) 2015-2022 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++17 } }
  19
  20 #include <numeric>
  21
  22 #ifndef __cpp_lib_gcd_lcm
  23 # error "Feature-test macro for gcd missing"
  24 #elif __cpp_lib_gcd_lcm != 201606
  25 # error "Feature-test macro for gcd has wrong value"
  26 #endif
  27
  28 using std::gcd;
  29 using std::is_same_v;
  30
  31 static_assert( gcd(1071, 462) == 21, "" );
  32 static_assert( gcd(2000, 20) == 20, "" );
  33 static_assert( gcd(2011, 17) == 1, "GCD of two primes is 1" );
  34 static_assert( gcd(200, 200) == 200, "GCD of equal numbers is that number" );
  35 static_assert( gcd(0, 13) == 13, "GCD of any number and 0 is that number" );
  36 static_assert( gcd(29, 0) == 29, "GCD of any number and 0 is that number" );
  37 static_assert( gcd(0, 0) == 0, "Zarro Boogs found" );
  38
  39 static_assert(gcd(1u, 2) == 1, "unsigned and signed");
  40 static_assert(gcd(9, 6u) == 3, "unsigned and signed");
  41 static_assert(gcd(3, 4u) == 1, "signed and unsigned");
  42 static_assert(gcd(32u, 24) == 8, "signed and unsigned");
  43 static_assert(gcd(1u, -2) == 1, "unsigned and negative");
  44 static_assert(gcd(-21, 28u) == 7, "unsigned and negative");
  45 static_assert(gcd(-3, 4u) == 1, "negative and unsigned");
  46 static_assert(gcd(33u, -44) == 11, "negative and unsigned");
  47 static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
  48 static_assert(gcd(54u, 36u) == 18, "unsigned and unsigned");
  49 static_assert(gcd(-5, -6) == 1, "negative and negative");
  50 static_assert(gcd(-50, -60) == 10, "negative and negative");
  51
  52 static_assert( is_same_v<decltype(gcd(1l, 1)), long> );
  53 static_assert( is_same_v<decltype(gcd(1ul, 1ull)), unsigned long long> );