+ return {};
+}
+
+
+void
+Content::add_path (boost::filesystem::path p)
+{
+ boost::mutex::scoped_lock lm (_mutex);
+ _paths.push_back (p);
+ boost::system::error_code ec;
+ auto last_write = boost::filesystem::last_write_time(p, ec);
+ _last_write_times.push_back (ec ? 0 : last_write);
+}
+
+
+bool
+Content::changed () const
+{
+ bool write_time_changed = false;
+ for (auto i = 0U; i < _paths.size(); ++i) {
+ if (boost::filesystem::last_write_time(_paths[i]) != last_write_time(i)) {
+ write_time_changed = true;
+ break;
+ }
+ }
+
+ return (write_time_changed || calculate_digest() != digest());