diff --git a/xybrid/data/graph.cpp b/xybrid/data/graph.cpp
index 674c83d..b767cd5 100644
--- a/xybrid/data/graph.cpp
+++ b/xybrid/data/graph.cpp
@@ -44,7 +44,7 @@ void Graph::saveData(QCborMap& m) const {
         QCborArray c;
 
         int idx = 0;
-        for (auto ch : children) {
+        for (auto& ch : children) {
             if (!ch->plugin) continue;
             indices[ch.get()] = idx++;
             c << ch->toCbor();
@@ -58,14 +58,14 @@ void Graph::saveData(QCborMap& m) const {
         // array { oIdx, dataType, pIdx, iIdx, dataType, pIdx }
         QCborArray cn;
 
-        for (auto ch : children) {
+        for (auto& ch : children) {
             if (!ch->plugin) continue; // already skipped over
             int idx = indices[ch.get()];
-            for (auto dt : ch->outputs) {
-                for (auto op : dt.second) {
+            for (auto& dt : ch->outputs) {
+                for (auto& op : dt.second) {
                     auto o = op.second;
                     o->cleanConnections(); // let's just do some groundskeeping here
-                    for (auto iw : o->connections) {
+                    for (auto& iw : o->connections) {
                         auto i = iw.lock();
                         QCborArray c;
                         c << idx;
diff --git a/xybrid/data/node.cpp b/xybrid/data/node.cpp
index 8f5f0db..494eb04 100644
--- a/xybrid/data/node.cpp
+++ b/xybrid/data/node.cpp
@@ -48,7 +48,7 @@ bool Port::connect(std::shared_ptr<Port> p) {
     // actual processing is always done on the input port, since that's where any limits are
     if (type == Output) return p->type == Input && p->connect(shared_from_this());
     if (!canConnectTo(p->dataType())) return false; // can't hook up to an incompatible data type
-    for (auto c : connections) if (c.lock() == p) return true; // I guess report success if already connected?
+    for (auto& c : connections) if (c.lock() == p) return true; // I guess report success if already connected?
     if (singleInput() && connections.size() > 0) return false; // reject multiple connections on single-input ports
     if (auto o = owner.lock(), po = p->owner.lock(); !o || !po || po->dependsOn(o)) return false; // no dependency loops!
     // actually hook up
@@ -118,7 +118,7 @@ QCborMap Node::multiToCbor(std::vector<std::shared_ptr<Node>>& v) {
     { /* nodes */ } {
         QCborArray nm;
         int idx = 0;
-        for (auto n : v) {
+        for (auto& n : v) {
             if (n->isVolatile()) continue; // skip things with volatile locality (i/o ports etc.)
             indices[n.get()] = idx++;
             nm << n->toCbor();
@@ -129,21 +129,21 @@ QCborMap Node::multiToCbor(std::vector<std::shared_ptr<Node>>& v) {
     // exported samples
     if (auto v = Sample::finishExport(); !v.empty()) {
         QCborMap smp;
-        for (auto s : v) smp[QCborValue(s->uuid)] = s->toCbor();
+        for (auto& s : v) smp[QCborValue(s->uuid)] = s->toCbor();
         m[qs("samples")] = smp;
     }
 
     { /* connections */ } {
         QCborArray cm;
 
-        for (auto n : v) {
+        for (auto& n : v) {
             if (n->isVolatile()) continue; // already skipped
             int idx = indices[n.get()];
-            for (auto dt : n->outputs) {
-                for (auto op : dt.second) {
+            for (auto& dt : n->outputs) {
+                for (auto& op : dt.second) {
                     auto o = op.second;
                     o->cleanConnections(); // let's just do some groundskeeping here
-                    for (auto iw : o->connections) {
+                    for (auto& iw : o->connections) {
                         auto i = iw.lock();
                         if (auto in = indices.find(i->owner.lock().get()); in != indices.end()) { // only connections within the collection
                             QCborArray c;
@@ -166,7 +166,7 @@ QCborMap Node::multiToCbor(std::vector<std::shared_ptr<Node>>& v) {
     { /* center */ } {
         int count = 0;
         QPoint center;
-        for (auto n : v) {
+        for (auto& n : v) {
             if (n->isVolatile()) continue;
             center += QPoint(n->x, n->y);
             count++;
@@ -227,7 +227,7 @@ std::vector<std::shared_ptr<Node>> Node::multiFromCbor(const QCborMap& m, std::s
 
     if (!cp.isNull()) { // offset and such
         QPoint off = cp - center;
-        for (auto n : v) {
+        for (auto& n : v) {
             n->x += off.x();
             n->y += off.y();
         }
@@ -305,7 +305,7 @@ void Node::collapsePorts(Port::Type t, Port::DataType dt) {
     if (mdt == m.end()) return; // nothing there
     auto& mm = mdt->second;
     uint8_t maxIdx = 0;
-    for (auto p : mm) maxIdx = std::max(maxIdx, p.first);
+    for (auto& p : mm) maxIdx = std::max(maxIdx, p.first);
     uint8_t firstUnused = 255;
     for (uint8_t i = 0; i <= maxIdx; i++) {
         if (auto pi = mm.find(i); pi != mm.end()) {
@@ -347,7 +347,7 @@ bool Node::try_process(bool checkDependencies) {
 
     if (checkDependencies) { // check if dependencies are done
         auto checkInput = Util::yCombinator([tick_this](auto checkInput, std::shared_ptr<Port> p) -> bool {
-            for (auto c : p->connections) { // check each connection; if node valid...
+            for (auto& c : p->connections) { // check each connection; if node valid...
                 if (auto cp = c.lock(); cp) {
                     if (auto n = cp->owner.lock(); n) {
                         if (n->tick_last != tick_this) return false; // if node itself not yet processed, check failed
@@ -363,7 +363,7 @@ bool Node::try_process(bool checkDependencies) {
             return true;
         });
 
-        for (auto t : inputs) for (auto p : t.second) if (!checkInput(p.second)) return false;
+        for (auto& t : inputs) for (auto& p : t.second) if (!checkInput(p.second)) return false;
 
         /*for (auto& t : inputs) {
             for (auto& p : t.second) {
diff --git a/xybrid/data/porttypes.cpp b/xybrid/data/porttypes.cpp
index 26526a7..74329fa 100644
--- a/xybrid/data/porttypes.cpp
+++ b/xybrid/data/porttypes.cpp
@@ -30,7 +30,7 @@ void AudioPort::pull() {
         bufR = &bufL[ts]; // for some reason just adding the size wonks out
         memset(bufL, 0, s*2); // clear buffers
 
-        for (auto c : connections) { // mix
+        for (auto& c : connections) { // mix
             if (auto p = std::static_pointer_cast<AudioPort>(c.lock()); p && p->dataType() == Audio) {
                 p->pull();
                 for (size_t i = 0; i < ts; i++) {
@@ -62,7 +62,7 @@ void CommandPort::pull() {
 
     size = 0;
     if (type == Input) {
-        for (auto c : connections) {
+        for (auto& c : connections) {
             if (auto p = std::static_pointer_cast<CommandPort>(c.lock()); p && p->dataType() == Command) {
                 p->pull();
                 data = p->data; // just repoint to input's buffer
diff --git a/xybrid/ui/gadgets/sampleselectorgadget.cpp b/xybrid/ui/gadgets/sampleselectorgadget.cpp
index 622339e..2a0ae11 100644
--- a/xybrid/ui/gadgets/sampleselectorgadget.cpp
+++ b/xybrid/ui/gadgets/sampleselectorgadget.cpp
@@ -138,7 +138,7 @@ void SampleSelectorGadget::mousePressEvent(QGraphicsSceneMouseEvent* e) {
             m->addAction("(no sample)", this, [this] { setSample(nullptr); });
             m->addSeparator();
             DirectoryNode root;
-            for (auto s : qAsConst(project->samples)) root.placeData(s->name, s->uuid);
+            for (auto& s : qAsConst(project->samples)) root.placeData(s->name, s->uuid);
             root.sortTree();
 
             buildSubmenu(&root, m);
diff --git a/xybrid/ui/gadgets/selectorgadget.cpp b/xybrid/ui/gadgets/selectorgadget.cpp
index cfcb880..fbf75c0 100644
--- a/xybrid/ui/gadgets/selectorgadget.cpp
+++ b/xybrid/ui/gadgets/selectorgadget.cpp
@@ -57,7 +57,7 @@ void SelectorGadget::mousePressEvent(QGraphicsSceneMouseEvent* e) {
         std::vector<Entry> v = fGetList ? fGetList() : std::vector<Entry>();
         if (v.empty()) m->addAction("(no entries)")->setDisabled(true);
         else {
-            for (auto e : v) {
+            for (auto& e : v) {
                 if (_entry.first == e.first) {
                     m->addAction(e.second)->setDisabled(true);
                 } else m->addAction(e.second, this, [this, e] {
diff --git a/xybrid/ui/patchboard/patchboardscene.cpp b/xybrid/ui/patchboard/patchboardscene.cpp
index 1effa51..e343241 100644
--- a/xybrid/ui/patchboard/patchboardscene.cpp
+++ b/xybrid/ui/patchboard/patchboardscene.cpp
@@ -115,7 +115,7 @@ PatchboardScene::PatchboardScene(QGraphicsView* parent, const std::shared_ptr<Xy
         auto v = Node::multiFromCbor(QCborValue::fromCbor(data->data("xybrid-internal/x-graph-copy")), graph, center);
 
         setSelectionArea(QPainterPath()); // deselect all
-        for (auto n : v) { // and select pasted objects
+        for (auto& n : v) { // and select pasted objects
             auto o = new NodeObject(n);
             addItem(o);
             o->setSelected(true);
@@ -225,7 +225,7 @@ void PatchboardScene::refresh() {
     // build scene from graph
     clear();
 
-    for (auto n : graph->children) {
+    for (auto& n : graph->children) {
         auto* o = new NodeObject(n);
         addItem(o);
     }
diff --git a/xybrid/ui/samplelistmodel.cpp b/xybrid/ui/samplelistmodel.cpp
index defe9e4..bca0b8f 100644
--- a/xybrid/ui/samplelistmodel.cpp
+++ b/xybrid/ui/samplelistmodel.cpp
@@ -99,7 +99,7 @@ void SampleListModel::refresh() {
     root = std::make_shared<DirectoryNode>();
     auto* project = window->getProject().get();
     if (!project) return;
-    for (auto s : qAsConst(project->samples)) root->placeData(s->name, s->uuid);
+    for (auto& s : qAsConst(project->samples)) root->placeData(s->name, s->uuid);
     root->sortTree();
 
     view->setCurrentIndex(QModelIndex());
@@ -237,7 +237,7 @@ bool SampleListModel::dropMimeData(const QMimeData *data, Qt::DropAction action,
 
         QList<QUrl> urls = data->urls();
         bool success = false;
-        for (auto u : urls) {
+        for (auto& u : urls) {
             if (!u.isLocalFile()) continue;
             auto smp = Sample::fromFile(u.toLocalFile());
             if (smp) { // valid sample returned