+ // local helper class
+ class opt_helper {
+ public:
+ template <typename T>
+ static bool parse_arg(char opt, const char *arg, T& val);
+ static const char* on_off(bool b);
+ const char* descr(const char* str);
+ template <typename T>
+ const char* val_or_string(const T& val, const char* str,
+ const T& deflt = 0);
+ template <typename T>
+ static bool nol_find_prefix(const T& nol, const char* descr,
+ std::string& name);
+
+ private:
+ std::string descr_str;
+ std::string val_or_string_str;
+ };
+
+} // namespace
+
+template <typename T>
+bool opt_helper::parse_arg(char opt, const char *arg, T& val)
+{
+ std::istringstream str(arg);
+ bool result = (str >> val) && str.eof();
+ if (!result)
+ XBT_ERROR("invalid argument for option '-%c' -- \"%s\"", opt, arg);
+ return result;
+}
+
+const char* opt_helper::on_off(bool b)
+{
+ return b ? "on" : "off";
+}
+
+const char* opt_helper::descr(const char* str)
+{
+ const int descr_width = 40;
+ std::string& res = descr_str;
+ res = str;
+ res.resize(descr_width, '.');
+ return res.c_str();
+}
+
+template <typename T>
+const char* opt_helper::val_or_string(const T& val, const char* str,
+ const T& deflt)
+{
+ std::string& res = val_or_string_str;
+ if (val != deflt) {
+ std::ostringstream oss;
+ oss << val;
+ res = oss.str();
+ } else {
+ res = str;
