core: make most for loops use const references (#7527)

why not let the compiler optimise things for us at hyprspeeds when we
can.

src/protocols/core/Compositor.cpp

@@ -260,7 +260,7 @@ void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> nodes, std
     for (auto& n : nodes) {
         std::erase_if(n->subsurfaces, [](const auto& e) { return e.expired(); });
         // subsurfaces is sorted lowest -> highest
-        for (auto& c : n->subsurfaces) {
+        for (auto const& c : n->subsurfaces) {
             if (c->zIndex >= 0)
                 break;
             if (c->surface.expired())
@@ -274,7 +274,7 @@ void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> nodes, std
 
     nodes2.clear();
 
-    for (auto& n : nodes) {
+    for (auto const& n : nodes) {
         Vector2D offset = {};
         if (n->role->role() == SURFACE_ROLE_SUBSURFACE) {
             auto subsurface = ((CSubsurfaceRole*)n->role.get())->subsurface.lock();
@@ -284,8 +284,8 @@ void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> nodes, std
         fn(n, offset, data);
     }
 
-    for (auto& n : nodes) {
-        for (auto& c : n->subsurfaces) {
+    for (auto const& n : nodes) {
+        for (auto const& c : n->subsurfaces) {
             if (c->zIndex < 0)
                 continue;
             if (c->surface.expired())

src/protocols/core/DataDevice.cpp

@@ -306,7 +306,7 @@ CWLDataDeviceManagerResource::CWLDataDeviceManagerResource(SP<CWlDataDeviceManag
 
         RESOURCE->self = RESOURCE;
 
-        for (auto& s : sources) {
+        for (auto const& s : sources) {
             if (!s)
                 continue;
             s->device = RESOURCE;
@@ -390,7 +390,7 @@ void CWLDataDeviceProtocol::onDestroyDataSource(WP<CWLDataSourceResource> source
 }
 
 void CWLDataDeviceProtocol::setSelection(SP<IDataSource> source) {
-    for (auto& o : m_vOffers) {
+    for (auto const& o : m_vOffers) {
         if (o->source && o->source->hasDnd())
             continue;
         o->dead = true;
@@ -439,7 +439,7 @@ void CWLDataDeviceProtocol::updateSelection() {
 }
 
 void CWLDataDeviceProtocol::onKeyboardFocus() {
-    for (auto& o : m_vOffers) {
+    for (auto const& o : m_vOffers) {
         o->dead = true;
     }
 
@@ -606,7 +606,7 @@ bool CWLDataDeviceProtocol::wasDragSuccessful() {
     if (!dnd.focusedDevice || !dnd.currentSource)
         return false;
 
-    for (auto& o : m_vOffers) {
+    for (auto const& o : m_vOffers) {
         if (o->dead || !o->source || !o->source->hasDnd())
             continue;
 

src/protocols/core/Output.cpp

@@ -118,7 +118,7 @@ bool CWLOutputProtocol::isDefunct() {
 }
 
 void CWLOutputProtocol::sendDone() {
-    for (auto& r : m_vOutputs) {
+    for (auto const& r : m_vOutputs) {
         r->resource->sendDone();
     }
 }

src/protocols/core/Seat.cpp

@@ -172,7 +172,7 @@ void CWLPointerResource::sendLeave() {
     if (!PROTO::data->dndActive()) {
         timespec now;
         clock_gettime(CLOCK_MONOTONIC, &now);
-        for (auto& b : pressedButtons) {
+        for (auto const& b : pressedButtons) {
             sendButton(now.tv_sec * 1000 + now.tv_nsec / 1000000, b, WL_POINTER_BUTTON_STATE_RELEASED);
         }
     }