Fix unnecessary parameter copies

30 files changed, 120 insertions, 118 deletions

diff --git a/.clang-tidy b/.clang-tidy
index badd2fd1..f3b3a33f 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -67,7 +67,6 @@ Checks: >
   -modernize-use-default-member-init,
   -modernize-use-trailing-return-type,
   -modernize-use-using,
-  -performance-unnecessary-value-param,
   -portability-simd-intrinsics,
   -readability-avoid-const-params-in-decls,
   -readability-const-return-type,
diff --git a/ingen/Interface.hpp b/ingen/Interface.hpp
index 981b7dd5..10d7d4bf 100644
--- a/ingen/Interface.hpp
+++ b/ingen/Interface.hpp
@@ -57,7 +57,7 @@ public:
 
 	virtual SPtr<Interface> respondee() const { return SPtr<Interface>(); }
 
-	virtual void set_respondee(SPtr<Interface> respondee) {}
+	virtual void set_respondee(const SPtr<Interface>& respondee) {}
 
 	virtual void message(const Message& msg) = 0;
 
diff --git a/ingen/Log.hpp b/ingen/Log.hpp
index e6bc2b39..d668e873 100644
--- a/ingen/Log.hpp
+++ b/ingen/Log.hpp
@@ -90,7 +90,7 @@ public:
 
 	void set_flush(bool f) { _flush = f; }
 	void set_trace(bool f) { _trace = f; }
-	void set_sink(Sink s)  { _sink = s; }
+	void set_sink(Sink s)  { _sink = std::move(s); }
 
 private:
 	void print(FILE* stream, const std::string& msg) const;
diff --git a/ingen/Tee.hpp b/ingen/Tee.hpp
index bf3fd335..b13b9e95 100644
--- a/ingen/Tee.hpp
+++ b/ingen/Tee.hpp
@@ -40,7 +40,7 @@ public:
 		return _sinks.front()->respondee();
 	}
 
-	void set_respondee(SPtr<Interface> respondee) override {
+	void set_respondee(const SPtr<Interface>& respondee) override {
 		_sinks.front()->set_respondee(respondee);
 	}
 
diff --git a/ingen/World.hpp b/ingen/World.hpp
index a2906525..b5fc7350 100644
--- a/ingen/World.hpp
+++ b/ingen/World.hpp
@@ -89,9 +89,10 @@ public:
 	virtual bool run_module(const char* name);
 
 	/** A function to create a new remote Interface. */
-	typedef SPtr<Interface> (*InterfaceFactory)(World&          world,
-	                                            const URI&      engine_uri,
-	                                            SPtr<Interface> respondee);
+	typedef SPtr<Interface> (*InterfaceFactory)(
+	    World&                 world,
+	    const URI&             engine_uri,
+	    const SPtr<Interface>& respondee);
 
 	/** Register an InterfaceFactory (for module implementations). */
 	virtual void add_interface_factory(const std::string& scheme,
diff --git a/ingen/client/ClientStore.hpp b/ingen/client/ClientStore.hpp
index 9576cd3c..109bd835 100644
--- a/ingen/client/ClientStore.hpp
+++ b/ingen/client/ClientStore.hpp
@@ -59,9 +59,9 @@ class INGEN_API ClientStore : public Store
                             , public INGEN_TRACKABLE {
 public:
 	ClientStore(
-		URIs&                    uris,
-		Log&                     log,
-		SPtr<SigClientInterface> emitter = SPtr<SigClientInterface>());
+	    URIs&                           uris,
+	    Log&                            log,
+	    const SPtr<SigClientInterface>& emitter = SPtr<SigClientInterface>());
 
 	URI uri() const override { return URI("ingen:/clients/store"); }
 
@@ -75,7 +75,7 @@ public:
 
 	SPtr<const Plugins> plugins() const              { return _plugins; }
 	SPtr<Plugins>       plugins()                    { return _plugins; }
-	void                set_plugins(SPtr<Plugins> p) { _plugins = p; }
+	void                set_plugins(SPtr<Plugins> p) { _plugins = std::move(p); }
 
 	URIs& uris() { return _uris; }
 
@@ -108,10 +108,10 @@ private:
 	SPtr<PluginModel> _plugin(const Atom& uri);
 	SPtr<Resource>    _resource(const URI& uri);
 
-	void add_object(SPtr<ObjectModel> object);
+	void add_object(const SPtr<ObjectModel>& object);
 	SPtr<ObjectModel> remove_object(const Raul::Path& path);
 
-	void add_plugin(SPtr<PluginModel> pm);
+	void add_plugin(const SPtr<PluginModel>& pm);
 
 	SPtr<GraphModel> connection_graph(const Raul::Path& tail_path,
 	                                  const Raul::Path& head_path);
diff --git a/ingen/client/PluginModel.hpp b/ingen/client/PluginModel.hpp
index dc0c724f..10ab3a6a 100644
--- a/ingen/client/PluginModel.hpp
+++ b/ingen/client/PluginModel.hpp
@@ -82,8 +82,8 @@ public:
 
 	bool has_ui() const;
 
-	SPtr<PluginUI> ui(ingen::World&               world,
-	                  SPtr<const BlockModel> block) const;
+	SPtr<PluginUI>
+	ui(ingen::World& world, const SPtr<const BlockModel>& block) const;
 
 	std::string documentation(bool html) const;
 	std::string port_documentation(uint32_t index, bool html) const;
@@ -104,7 +104,7 @@ public:
 
 protected:
 	friend class ClientStore;
-	void set(SPtr<PluginModel> p);
+	void set(const SPtr<PluginModel>& p);
 
 	void add_preset(const URI& uri, const std::string& label);
 
diff --git a/ingen/client/PluginUI.hpp b/ingen/client/PluginUI.hpp
index b5d467ea..70ff7274 100644
--- a/ingen/client/PluginUI.hpp
+++ b/ingen/client/PluginUI.hpp
@@ -53,9 +53,9 @@ public:
 	 * connected first.  The caller should connect to signal_property_changed,
 	 * then call instantiate().
 	 */
-	static SPtr<PluginUI> create(ingen::World&          world,
-	                             SPtr<const BlockModel> block,
-	                             const LilvPlugin*      plugin);
+	static SPtr<PluginUI> create(ingen::World&                 world,
+	                             const SPtr<const BlockModel>& block,
+	                             const LilvPlugin*             plugin);
 
 	/** Instantiate the UI.
 	 *
diff --git a/ingen/client/SocketClient.hpp b/ingen/client/SocketClient.hpp
index 092ef9d2..8e551821 100644
--- a/ingen/client/SocketClient.hpp
+++ b/ingen/client/SocketClient.hpp
@@ -29,27 +29,27 @@ namespace client {
 class INGEN_API SocketClient : public SocketWriter
 {
 public:
-	SocketClient(World&             world,
-	             const URI&         uri,
-	             SPtr<Raul::Socket> sock,
-	             SPtr<Interface>    respondee)
-		: SocketWriter(world.uri_map(), world.uris(), uri, sock)
-		, _respondee(respondee)
-		, _reader(world, *respondee.get(), sock)
+	SocketClient(World&                    world,
+	             const URI&                uri,
+	             const SPtr<Raul::Socket>& sock,
+	             const SPtr<Interface>&    respondee)
+	    : SocketWriter(world.uri_map(), world.uris(), uri, sock)
+	    , _respondee(respondee)
+	    , _reader(world, *respondee.get(), sock)
 	{}
 
 	SPtr<Interface> respondee() const override {
 		return _respondee;
 	}
 
-	void set_respondee(SPtr<Interface> respondee) override {
+	void set_respondee(const SPtr<Interface>& respondee) override {
 		_respondee = respondee;
 	}
 
 	static SPtr<ingen::Interface>
-	new_socket_interface(ingen::World&          world,
-	                     const URI&             uri,
-	                     SPtr<ingen::Interface> respondee)
+	new_socket_interface(ingen::World&                 world,
+	                     const URI&                    uri,
+	                     const SPtr<ingen::Interface>& respondee)
 	{
 		const Raul::Socket::Type type = (uri.scheme() == "unix"
 		                                 ? Raul::Socket::Type::UNIX
diff --git a/src/client/ClientStore.cpp b/src/client/ClientStore.cpp
index e494e874..a0c30c85 100644
--- a/src/client/ClientStore.cpp
+++ b/src/client/ClientStore.cpp
@@ -35,9 +35,9 @@
 namespace ingen {
 namespace client {
 
-ClientStore::ClientStore(URIs&                    uris,
-                         Log&                     log,
-                         SPtr<SigClientInterface> emitter)
+ClientStore::ClientStore(URIs&                           uris,
+                         Log&                            log,
+                         const SPtr<SigClientInterface>& emitter)
 	: _uris(uris)
 	, _log(log)
 	, _emitter(emitter)
@@ -57,7 +57,7 @@ ClientStore::clear()
 }
 
 void
-ClientStore::add_object(SPtr<ObjectModel> object)
+ClientStore::add_object(const SPtr<ObjectModel>& object)
 {
 	// If we already have "this" object, merge the existing one into the new
 	// one (with precedence to the new values).
@@ -189,7 +189,7 @@ ClientStore::resource(const URI& uri) const
 }
 
 void
-ClientStore::add_plugin(SPtr<PluginModel> pm)
+ClientStore::add_plugin(const SPtr<PluginModel>& pm)
 {
 	SPtr<PluginModel> existing = _plugin(pm->uri());
 	if (existing) {
diff --git a/src/client/PluginModel.cpp b/src/client/PluginModel.cpp
index 6c6b9748..92a1b295 100644
--- a/src/client/PluginModel.cpp
+++ b/src/client/PluginModel.cpp
@@ -153,7 +153,7 @@ PluginModel::get_property(const URI& key) const
 }
 
 void
-PluginModel::set(SPtr<PluginModel> p)
+PluginModel::set(const SPtr<PluginModel>& p)
 {
 	_type = p->_type;
 
@@ -242,8 +242,7 @@ PluginModel::has_ui() const
 }
 
 SPtr<PluginUI>
-PluginModel::ui(ingen::World&          world,
-                SPtr<const BlockModel> block) const
+PluginModel::ui(ingen::World& world, const SPtr<const BlockModel>& block) const
 {
 	if (!_lilv_plugin) {
 		return SPtr<PluginUI>();
diff --git a/src/client/PluginUI.cpp b/src/client/PluginUI.cpp
index bc58020a..6fdf76c5 100644
--- a/src/client/PluginUI.cpp
+++ b/src/client/PluginUI.cpp
@@ -178,9 +178,9 @@ PluginUI::~PluginUI()
 }
 
 SPtr<PluginUI>
-PluginUI::create(ingen::World&          world,
-                 SPtr<const BlockModel> block,
-                 const LilvPlugin*      plugin)
+PluginUI::create(ingen::World&                 world,
+                 const SPtr<const BlockModel>& block,
+                 const LilvPlugin*             plugin)
 {
 	if (!PluginUI::ui_host) {
 		PluginUI::ui_host = suil_host_new(lv2_ui_write,
diff --git a/src/gui/App.cpp b/src/gui/App.cpp
index 92279906..fa48cb18 100644
--- a/src/gui/App.cpp
+++ b/src/gui/App.cpp
@@ -160,7 +160,7 @@ App::run()
 }
 
 void
-App::attach(SPtr<ingen::Interface> client)
+App::attach(const SPtr<ingen::Interface>& client)
 {
 	assert(!_client);
 	assert(!_store);
diff --git a/src/gui/App.hpp b/src/gui/App.hpp
index e9d83cfd..3149f169 100644
--- a/src/gui/App.hpp
+++ b/src/gui/App.hpp
@@ -75,7 +75,7 @@ public:
 
 	void error_message(const std::string& str);
 
-	void attach(SPtr<ingen::Interface> client);
+	void attach(const SPtr<ingen::Interface>& client);
 
 	void detach();
 
diff --git a/src/gui/Arc.cpp b/src/gui/Arc.cpp
index d811bd22..b436dd26 100644
--- a/src/gui/Arc.cpp
+++ b/src/gui/Arc.cpp
@@ -24,12 +24,11 @@
 namespace ingen {
 namespace gui {
 
-Arc::Arc(Ganv::Canvas&                canvas,
-         SPtr<const client::ArcModel> model,
-         Ganv::Node*                  src,
-         Ganv::Node*                  dst)
-	: Ganv::Edge(canvas, src, dst)
-	, _arc_model(model)
+Arc::Arc(Ganv::Canvas&                       canvas,
+         const SPtr<const client::ArcModel>& model,
+         Ganv::Node*                         src,
+         Ganv::Node*                         dst)
+    : Ganv::Edge(canvas, src, dst), _arc_model(model)
 {
 	SPtr<const client::ObjectModel> tparent = model->tail()->parent();
 	SPtr<const client::BlockModel>  tparent_block;
diff --git a/src/gui/Arc.hpp b/src/gui/Arc.hpp
index 453985fc..7e33384b 100644
--- a/src/gui/Arc.hpp
+++ b/src/gui/Arc.hpp
@@ -35,10 +35,10 @@ namespace gui {
 class Arc : public Ganv::Edge
 {
 public:
-	Arc(Ganv::Canvas&                canvas,
-	    SPtr<const client::ArcModel> model,
-	    Ganv::Node*                  src,
-	    Ganv::Node*                  dst);
+	Arc(Ganv::Canvas&                       canvas,
+	    const SPtr<const client::ArcModel>& model,
+	    Ganv::Node*                         src,
+	    Ganv::Node*                         dst);
 
 	SPtr<const client::ArcModel> model() const { return _arc_model; }
 
diff --git a/src/gui/BreadCrumbs.cpp b/src/gui/BreadCrumbs.cpp
index a4a1b2fb..5dbdab17 100644
--- a/src/gui/BreadCrumbs.cpp
+++ b/src/gui/BreadCrumbs.cpp
@@ -58,7 +58,7 @@ BreadCrumbs::view(const Raul::Path& path)
  * children preserved.
  */
 void
-BreadCrumbs::build(Raul::Path path, SPtr<GraphView> view)
+BreadCrumbs::build(const Raul::Path& path, const SPtr<GraphView>& view)
 {
 	bool old_enable_signal = _enable_signal;
 	_enable_signal = false;
@@ -156,8 +156,7 @@ BreadCrumbs::build(Raul::Path path, SPtr<GraphView> view)
  * match, otherwise ignoring `view`.
  */
 BreadCrumbs::BreadCrumb*
-BreadCrumbs::create_crumb(const Raul::Path& path,
-                          SPtr<GraphView>   view)
+BreadCrumbs::create_crumb(const Raul::Path& path, const SPtr<GraphView>& view)
 {
 	BreadCrumb* but = manage(
 		new BreadCrumb(path,
diff --git a/src/gui/BreadCrumbs.hpp b/src/gui/BreadCrumbs.hpp
index 63872a78..f359b971 100644
--- a/src/gui/BreadCrumbs.hpp
+++ b/src/gui/BreadCrumbs.hpp
@@ -47,7 +47,7 @@ public:
 
 	SPtr<GraphView> view(const Raul::Path& path);
 
-	void build(Raul::Path path, SPtr<GraphView> view);
+	void build(const Raul::Path& path, const SPtr<GraphView>& view);
 
 	sigc::signal<void, const Raul::Path&, SPtr<GraphView> > signal_graph_selected;
 
@@ -64,9 +64,10 @@ private:
 	class BreadCrumb : public Gtk::ToggleButton
 	{
 	public:
-		BreadCrumb(const Raul::Path& path, SPtr<GraphView> view = SPtr<GraphView>())
-			: _path(path)
-			, _view(view)
+		BreadCrumb(const Raul::Path&      path,
+		           const SPtr<GraphView>& view = SPtr<GraphView>())
+		    : _path(path)
+		    , _view(view)
 		{
 			assert(!view || view->graph()->path() == path);
 			set_border_width(0);
@@ -75,7 +76,7 @@ private:
 			show_all();
 		}
 
-		void set_view(SPtr<GraphView> view) {
+		void set_view(const SPtr<GraphView>& view) {
 			assert(!view || view->graph()->path() == _path);
 			_view = view;
 		}
@@ -100,8 +101,8 @@ private:
 		SPtr<GraphView> _view;
 	};
 
-	BreadCrumb* create_crumb(const Raul::Path& path,
-	                         SPtr<GraphView>   view = SPtr<GraphView>());
+	BreadCrumb* create_crumb(const Raul::Path&      path,
+	                         const SPtr<GraphView>& view = SPtr<GraphView>());
 
 	void breadcrumb_clicked(BreadCrumb* crumb);
 
diff --git a/src/gui/ConnectWindow.cpp b/src/gui/ConnectWindow.cpp
index 209475e0..fc9e7cab 100644
--- a/src/gui/ConnectWindow.cpp
+++ b/src/gui/ConnectWindow.cpp
@@ -129,7 +129,7 @@ ConnectWindow::ingen_response(int32_t            id,
 }
 
 void
-ConnectWindow::set_connected_to(SPtr<ingen::Interface> engine)
+ConnectWindow::set_connected_to(const SPtr<ingen::Interface>& engine)
 {
 	_app->world().set_interface(engine);
 
diff --git a/src/gui/ConnectWindow.hpp b/src/gui/ConnectWindow.hpp
index 882e0142..481e4d83 100644
--- a/src/gui/ConnectWindow.hpp
+++ b/src/gui/ConnectWindow.hpp
@@ -57,7 +57,7 @@ public:
 	ConnectWindow(BaseObjectType*            cobject,
 	              Glib::RefPtr<Gtk::Builder> xml);
 
-	void set_connected_to(SPtr<ingen::Interface> engine);
+	void set_connected_to(const SPtr<ingen::Interface>& engine);
 	void start(App& app, ingen::World& world);
 
 	bool attached()  const { return _finished_connecting; }
diff --git a/src/gui/GraphBox.cpp b/src/gui/GraphBox.cpp
index 7fe1a643..7856932d 100644
--- a/src/gui/GraphBox.cpp
+++ b/src/gui/GraphBox.cpp
@@ -195,7 +195,7 @@ GraphBox::~GraphBox()
 }
 
 SPtr<GraphBox>
-GraphBox::create(App& app, SPtr<const GraphModel> graph)
+GraphBox::create(App& app, const SPtr<const GraphModel>& graph)
 {
 	GraphBox* result = nullptr;
 	Glib::RefPtr<Gtk::Builder> xml = WidgetFactory::create("graph_win");
@@ -248,7 +248,8 @@ GraphBox::set_status_text(const std::string& text)
 }
 
 void
-GraphBox::set_graph_from_path(const Raul::Path& path, SPtr<GraphView> view)
+GraphBox::set_graph_from_path(const Raul::Path&      path,
+                              const SPtr<GraphView>& view)
 {
 	if (view) {
 		assert(view->graph()->path() == path);
@@ -267,8 +268,8 @@ GraphBox::set_graph_from_path(const Raul::Path& path, SPtr<GraphView> view)
  * If `view` is null, a new view will be created.
  */
 void
-GraphBox::set_graph(SPtr<const GraphModel> graph,
-                    SPtr<GraphView>        view)
+GraphBox::set_graph(const SPtr<const GraphModel>& graph,
+                    const SPtr<GraphView>&        view)
 {
 	if (!graph || graph == _graph) {
 		return;
@@ -355,7 +356,7 @@ GraphBox::set_graph(SPtr<const GraphModel> graph,
 }
 
 void
-GraphBox::graph_port_added(SPtr<const PortModel> port)
+GraphBox::graph_port_added(const SPtr<const PortModel>& port)
 {
 	if (port->is_input() && _app->can_control(port.get())) {
 		_menu_view_control_window->property_sensitive() = true;
@@ -363,7 +364,7 @@ GraphBox::graph_port_added(SPtr<const PortModel> port)
 }
 
 void
-GraphBox::graph_port_removed(SPtr<const PortModel> port)
+GraphBox::graph_port_removed(const SPtr<const PortModel>& port)
 {
 	if (!(port->is_input() && _app->can_control(port.get()))) {
 		return;
diff --git a/src/gui/GraphBox.hpp b/src/gui/GraphBox.hpp
index 93599e0b..e1f602b7 100644
--- a/src/gui/GraphBox.hpp
+++ b/src/gui/GraphBox.hpp
@@ -70,15 +70,15 @@ public:
 	         const Glib::RefPtr<Gtk::Builder>& xml);
 	~GraphBox();
 
-	static SPtr<GraphBox> create(
-		App& app, SPtr<const client::GraphModel> graph);
+	static SPtr<GraphBox>
+	create(App& app, const SPtr<const client::GraphModel>& graph);
 
 	void init_box(App& app);
 
 	void set_status_text(const std::string& text);
 
-	void set_graph(SPtr<const client::GraphModel> graph,
-	               SPtr<GraphView>                view);
+	void set_graph(const SPtr<const client::GraphModel>& graph,
+	               const SPtr<GraphView>&                view);
 
 	void set_window(GraphWindow* win) { _window = win; }
 
@@ -91,14 +91,15 @@ public:
 	void show_port_status(const client::PortModel* port,
 	                      const Atom&              value);
 
-	void set_graph_from_path(const Raul::Path& path, SPtr<GraphView> view);
+	void
+	set_graph_from_path(const Raul::Path& path, const SPtr<GraphView>& view);
 
 	void object_entered(const client::ObjectModel* model);
 	void object_left(const client::ObjectModel* model);
 
 private:
-	void graph_port_added(SPtr<const client::PortModel> port);
-	void graph_port_removed(SPtr<const client::PortModel> port);
+	void graph_port_added(const SPtr<const client::PortModel>& port);
+	void graph_port_removed(const SPtr<const client::PortModel>& port);
 	void property_changed(const URI& predicate, const Atom& value);
 	void show_status(const client::ObjectModel* model);
 
diff --git a/src/gui/GraphCanvas.cpp b/src/gui/GraphCanvas.cpp
index b89a2ddb..bb60caa5 100644
--- a/src/gui/GraphCanvas.cpp
+++ b/src/gui/GraphCanvas.cpp
@@ -841,7 +841,7 @@ GraphCanvas::menu_add_port(const string& sym_base,
 }
 
 void
-GraphCanvas::load_plugin(WPtr<PluginModel> weak_plugin)
+GraphCanvas::load_plugin(const WPtr<PluginModel>& weak_plugin)
 {
 	SPtr<PluginModel> plugin = weak_plugin.lock();
 	if (!plugin) {
diff --git a/src/gui/GraphCanvas.hpp b/src/gui/GraphCanvas.hpp
index b2529845..5b379ec7 100644
--- a/src/gui/GraphCanvas.hpp
+++ b/src/gui/GraphCanvas.hpp
@@ -96,7 +96,7 @@ private:
 	void menu_new_graph();
 	void menu_load_graph();
 	void menu_properties();
-	void load_plugin(WPtr<client::PluginModel> weak_plugin);
+	void load_plugin(const WPtr<client::PluginModel>& weak_plugin);
 
 	void build_menus();
 
diff --git a/src/gui/LoadPluginWindow.cpp b/src/gui/LoadPluginWindow.cpp
index 870288ac..acc34842 100644
--- a/src/gui/LoadPluginWindow.cpp
+++ b/src/gui/LoadPluginWindow.cpp
@@ -125,8 +125,8 @@ LoadPluginWindow::LoadPluginWindow(BaseObjectType*                   cobject,
 }
 
 void
-LoadPluginWindow::present(SPtr<const GraphModel> graph,
-                          Properties             data)
+LoadPluginWindow::present(const SPtr<const GraphModel>& graph,
+                          const Properties&             data)
 {
 	set_graph(graph);
 	_initial_data = data;
@@ -164,7 +164,7 @@ LoadPluginWindow::name_cleared(Gtk::EntryIconPosition pos, const GdkEventButton*
  * This function MUST be called before using the window in any way!
  */
 void
-LoadPluginWindow::set_graph(SPtr<const GraphModel> graph)
+LoadPluginWindow::set_graph(const SPtr<const GraphModel>& graph)
 {
 	if (_graph) {
 		_graph = graph;
@@ -199,7 +199,7 @@ LoadPluginWindow::on_show()
 }
 
 void
-LoadPluginWindow::set_plugins(SPtr<const ClientStore::Plugins> plugins)
+LoadPluginWindow::set_plugins(const SPtr<const ClientStore::Plugins>& plugins)
 {
 	_rows.clear();
 	_plugins_liststore->clear();
@@ -213,7 +213,7 @@ LoadPluginWindow::set_plugins(SPtr<const ClientStore::Plugins> plugins)
 }
 
 void
-LoadPluginWindow::new_plugin(SPtr<const PluginModel> pm)
+LoadPluginWindow::new_plugin(const SPtr<const PluginModel>& pm)
 {
 	if (is_visible()) {
 		add_plugin(pm);
@@ -223,7 +223,7 @@ LoadPluginWindow::new_plugin(SPtr<const PluginModel> pm)
 }
 
 static std::string
-get_project_name(SPtr<const PluginModel> plugin)
+get_project_name(const SPtr<const PluginModel>& plugin)
 {
 	std::string name;
 	if (plugin->lilv_plugin()) {
@@ -249,7 +249,7 @@ get_project_name(SPtr<const PluginModel> plugin)
 }
 
 static std::string
-get_author_name(SPtr<const PluginModel> plugin)
+get_author_name(const SPtr<const PluginModel>& plugin)
 {
 	std::string name;
 	if (plugin->lilv_plugin()) {
@@ -263,8 +263,8 @@ get_author_name(SPtr<const PluginModel> plugin)
 }
 
 void
-LoadPluginWindow::set_row(Gtk::TreeModel::Row&    row,
-                          SPtr<const PluginModel> plugin)
+LoadPluginWindow::set_row(Gtk::TreeModel::Row&           row,
+                          const SPtr<const PluginModel>& plugin)
 {
 	const URIs&       uris = _app->uris();
 	const Atom& name = plugin->get_property(uris.doap_name);
@@ -294,7 +294,7 @@ LoadPluginWindow::set_row(Gtk::TreeModel::Row&    row,
 }
 
 void
-LoadPluginWindow::add_plugin(SPtr<const PluginModel> plugin)
+LoadPluginWindow::add_plugin(const SPtr<const PluginModel>& plugin)
 {
 	if (plugin->lilv_plugin() && lilv_plugin_is_replaced(plugin->lilv_plugin())) {
 		return;
@@ -357,8 +357,8 @@ LoadPluginWindow::plugin_selection_changed()
  * sends the notification back.
  */
 string
-LoadPluginWindow::generate_module_name(SPtr<const PluginModel> plugin,
-                                       int                     offset)
+LoadPluginWindow::generate_module_name(const SPtr<const PluginModel>& plugin,
+                                       int                            offset)
 {
 	std::stringstream ss;
 	ss << plugin->default_block_symbol();
diff --git a/src/gui/LoadPluginWindow.hpp b/src/gui/LoadPluginWindow.hpp
index 49c61c76..78c52eba 100644
--- a/src/gui/LoadPluginWindow.hpp
+++ b/src/gui/LoadPluginWindow.hpp
@@ -54,13 +54,14 @@ public:
 	LoadPluginWindow(BaseObjectType*                   cobject,
 	                 const Glib::RefPtr<Gtk::Builder>& xml);
 
-	void set_graph(SPtr<const client::GraphModel> graph);
-	void set_plugins(SPtr<const client::ClientStore::Plugins> plugins);
+	void set_graph(const SPtr<const client::GraphModel>& graph);
 
-	void add_plugin(SPtr<const client::PluginModel> plugin);
+	void set_plugins(const SPtr<const client::ClientStore::Plugins>& plugins);
 
-	void present(SPtr<const client::GraphModel> graph,
-	             Properties                     data);
+	void add_plugin(const SPtr<const client::PluginModel>& plugin);
+
+	void present(const SPtr<const client::GraphModel>& graph,
+	             const Properties&                     data);
 
 protected:
 	void on_show() override;
@@ -109,10 +110,10 @@ private:
 	void name_changed();
 	void name_cleared(Gtk::EntryIconPosition pos, const GdkEventButton* event);
 
-	void set_row(Gtk::TreeModel::Row&            row,
-	             SPtr<const client::PluginModel> plugin);
+	void set_row(Gtk::TreeModel::Row&                   row,
+	             const SPtr<const client::PluginModel>& plugin);
 
-	void new_plugin(SPtr<const client::PluginModel> pm);
+	void new_plugin(const SPtr<const client::PluginModel>& pm);
 
 	void plugin_property_changed(const URI&  plugin,
 	                             const URI&  predicate,
@@ -122,8 +123,8 @@ private:
 	void plugin_selection_changed();
 
 	static std::string
-	generate_module_name(SPtr<const client::PluginModel> plugin,
-	                     int                             offset = 0);
+	generate_module_name(const SPtr<const client::PluginModel>& plugin,
+	                     int                                    offset = 0);
 
 	void load_plugin(const Gtk::TreeModel::iterator& iter);
 
diff --git a/src/server/Event.hpp b/src/server/Event.hpp
index 9c284e49..a8d6979b 100644
--- a/src/server/Event.hpp
+++ b/src/server/Event.hpp
@@ -107,17 +107,14 @@ public:
 	inline Engine& engine() { return _engine; }
 
 protected:
-	Event(Engine&                engine,
-	      const SPtr<Interface>& client,
-	      int32_t                id,
-	      FrameTime              time)
-		: _engine(engine)
-		, _next(nullptr)
-		, _request_client(std::move(client))
-		, _request_id(id)
-		, _time(time)
-		, _status(Status::NOT_PREPARED)
-		, _mode(Mode::NORMAL)
+	Event(Engine& engine, SPtr<Interface> client, int32_t id, FrameTime time)
+	    : _engine(engine)
+	    , _next(nullptr)
+	    , _request_client(std::move(client))
+	    , _request_id(id)
+	    , _time(time)
+	    , _status(Status::NOT_PREPARED)
+	    , _mode(Mode::NORMAL)
 	{}
 
 	/** Constructor for internal events only */
diff --git a/src/server/EventWriter.hpp b/src/server/EventWriter.hpp
index 85aa6f70..f0499f10 100644
--- a/src/server/EventWriter.hpp
+++ b/src/server/EventWriter.hpp
@@ -43,7 +43,7 @@ public:
 		return _respondee;
 	}
 
-	void set_respondee(SPtr<Interface> respondee) override {
+	void set_respondee(const SPtr<Interface>& respondee) override {
 		_respondee = respondee;
 	}
 
diff --git a/src/server/PortImpl.hpp b/src/server/PortImpl.hpp
index 86e98661..fba24f06 100644
--- a/src/server/PortImpl.hpp
+++ b/src/server/PortImpl.hpp
@@ -233,7 +233,11 @@ public:
 	BufferRef value_buffer(uint32_t voice) const;
 
 	BufferRef user_buffer(RunContext&) const { return _user_buffer; }
-	void      set_user_buffer(RunContext&, BufferRef b) { _user_buffer = b; }
+
+	void set_user_buffer(RunContext&, BufferRef b)
+	{
+		_user_buffer = std::move(b);
+	}
 
 	/** Return offset of the first value change after `offset`. */
 	virtual SampleCount next_value_offset(SampleCount offset,
diff --git a/src/server/SocketServer.hpp b/src/server/SocketServer.hpp
index f3f02a26..cd5afb25 100644
--- a/src/server/SocketServer.hpp
+++ b/src/server/SocketServer.hpp
@@ -36,9 +36,9 @@ namespace server {
 class SocketServer
 {
 public:
-	SocketServer(World&             world,
-	             server::Engine&    engine,
-	             SPtr<Raul::Socket> sock)
+	SocketServer(World&                    world,
+	             server::Engine&           engine,
+	             const SPtr<Raul::Socket>& sock)
 		: _engine(engine)
 		, _sink(world.conf().option("dump").get<int32_t>()
 		        ? SPtr<Interface>(