Function get_next_command

samples/memory_leak_test.cpp:12–24

std::string get_next_command() {
#ifdef READLINE_AVAILABLE
  char *input_raw;
  input_raw = readline("eval> ");
  add_history(input_raw);
  return std::string(input_raw);
#else
  std::string retval;
  std::cout << "eval> ";
  std::getline(std::cin, retval);
  return retval;
#endif
}

void function(void)
{