static bool fetch(const row& res, ColOrName col_or_name, std::unique_ptr<T>& v) { T tmp; if (res.fetch(col_or_name, tmp)) v.reset(new T(std::move(tmp))); return true; }
static bool fetch(const row& res, ColOrName col_or_name, boost::posix_time::ptime& v) { std::tm tm_struct; bool ret = res.fetch(col_or_name, tm_struct); if (ret) v = boost::posix_time::ptime_from_tm(tm_struct); return ret; }