Function validate_arg

src/common/cmdparse.cc:609–647

					     vector<T>,
					     T>>
bool validate_arg(const cmdmap_t& cmdmap,
		  const arg_desc_t& desc,
		  const std::string_view name,
		  const std::string_view type,
		  std::ostream& os)
{
  Value v;
  try {
    if (!cmd_getval(cmdmap, name, v)) {
      if constexpr (is_vector) {
	  // an empty list is acceptable.
	  return true;
	} else {
	if (auto req = desc.find("req");
	    req != end(desc) && req->second == "false") {
	  return true;
	} else {
	  os << "missing required parameter: '" << name << "'";
	  return false;
	}
      }
    }
  } catch (const bad_cmd_get& e) {
    return false;
  }
  auto validate = [&](const T& value) {
    if constexpr (is_same_v<std::string, T>) {
      return validate_str_arg(value, type, desc, os);
    } else if constexpr (is_same_v<int64_t, T> ||
			 is_same_v<double, T>) {
      return arg_in_range(value, desc, os);
    }
  };
  if constexpr(is_vector) {
    return find_if_not(begin(v), end(v), validate) == end(v);
  } else {
    return validate(v);
  }
}
} // anonymous namespace

bool validate_cmd(const std::string& desc,