Function is_empty

highs/util/stringutil.cpp:95–99

}

bool is_empty(char c, const std::string& chars) {
  size_t pos = chars.find_first_of(c);
  if (pos == std::string::npos || pos == chars.size()) return false;
  return true;
}

bool is_empty(std::string& str, const std::string& chars) {
  size_t pos = str.find_first_not_of(chars);