Fix websocket C++11ism

libs/surfaces/websockets/dispatcher.cc

@@ -95,7 +95,7 @@ WebsocketsDispatcher::update_all_nodes (Client client)
 
 				try {
 				    a_ctrl = strip.plugin (plugin_id).param_control (param_id);
-				} catch (ArdourMixerNotFoundException) {
+				} catch (ArdourMixerNotFoundException& err) {
 					continue;
 				}
 

libs/surfaces/websockets/feedback.cc

@@ -241,7 +241,7 @@ ArdourFeedback::observe_strip_plugins (uint32_t strip_id, ArdourMixerStrip::Plug
 				                          boost::bind<void> (PluginParamValueObserver (), this, strip_id, plugin_id, param_id,
 				                                             boost::weak_ptr<AutomationControl>(control)),
 				                          event_loop ());
-			} catch (ArdourMixerNotFoundException) {
+			} catch (ArdourMixerNotFoundException& e) {
 				/* ignore */
 			}
 		}

libs/surfaces/websockets/mixer.cc

@@ -101,7 +101,7 @@ ArdourMixerPlugin::param_control (uint32_t param_id) const
 	uint32_t                  control_id = plugin->nth_parameter (param_id, ok);
 
 	if (!ok || !plugin->parameter_is_input (control_id)) {
-		throw ArdourMixerNotFoundException("invalid automation control for param id = "
+		throw ArdourMixerNotFoundException ("invalid automation control for param id = "
 			+ boost::lexical_cast<std::string>(param_id));
 	}
 

libs/surfaces/websockets/mixer.h

@@ -28,7 +28,14 @@ namespace ArdourSurface {
 
 struct ArdourMixerNotFoundException : public virtual std::runtime_error
 {
-	using std::runtime_error::runtime_error; // XXX!
+public:
+	ArdourMixerNotFoundException (std::string const & what)
+		: runtime_error (what)
+		, _what (what)
+	{}
+	virtual const char* what() const throw() { return _what.c_str(); }
+private:
+	std::string _what;
 };
 
 class ArdourMixerPlugin