text: #include "grains.h"
  #include "test/catch.hpp"
  
  TEST_CASE("square_1")
  {
      REQUIRE(1ULL == grains::square(1));
  }
  
  // #if defined(EXERCISM_RUN_ALL_TESTS)
  TEST_CASE("square_2")
  {
      REQUIRE(2ULL == grains::square(2));
  }
  
  TEST_CASE("square_3")
  {
      REQUIRE(4ULL == grains::square(3));
  }
  
  TEST_CASE("square_4")
  {
      REQUIRE(8ULL == grains::square(4));
  }
  
  TEST_CASE("square_16")
  {
      REQUIRE(32768ULL == grains::square(16));
  }
  
  TEST_CASE("square_32")
  {
      REQUIRE(2147483648ULL == grains::square(32));
  }
  
  TEST_CASE("square_64")
  {
      REQUIRE(9223372036854775808ULL == grains::square(64));
  }
  
  TEST_CASE("total")
  {
      REQUIRE(18446744073709551615ULL == grains::total());
  }
  // #endif
  