bind_flag(std::string& value, const char* name, std::initializer_list<const char*> aliases, const char* description,
const std::map<std::string, std::string, std::less<>>& valid_values, F callback)
{
bind_flag(std::string& value, const char* name, std::initializer_list<const char*> aliases, const char* description,
const std::map<std::string, std::string, std::less<>>& valid_values, F callback)
{