libstdc++-v3/testsuite/26_numerics/gcd/105844.cc

   1 // { dg-do compile { target c++17 } }
   2 #include <numeric>
   3 #include <climits>
   4
   5 // PR libstdc++/105844
   6
   7 // |INT_MIN| can be represented in common_type_t<int, unsigned> i.e. unsigned.
   8 static_assert( std::gcd(INT_MIN, 2u) == 2 );
   9 static_assert( std::gcd(2u, INT_MIN) == 2 );
  10
  11 // |LLONG_MIN| can be represented in unsigned long long.
  12 static_assert( std::gcd(LLONG_MIN, 2ull) == 2 );
  13 static_assert( std::gcd(2ull, LLONG_MIN) == 2 );
  14
  15 // But |INT_MIN| cannot be represented in common_type<int, int> i.e. int.
  16 constexpr int a = std::gcd(INT_MIN, 1); // { dg-error "in .constexpr." }
  17 constexpr int b = std::gcd(1, INT_MIN); // { dg-error "in .constexpr." }
  18
  19 // And |LLONG_MIN| cannot be represented in long.
  20 constexpr long long c = std::gcd(LLONG_MIN, 1); // { dg-error "in .constexpr." }
  21 constexpr long long d = std::gcd(1, LLONG_MIN); // { dg-error "in .constexpr." }
  22
  23 // { dg-error "overflow" "" { target *-*-* } 0 }