Part: use empty() and isEmpty() instead of count() where possible

src/Mod/Part/App/TopoShapeCache.cpp

@@ -151,6 +151,10 @@ int TopoShapeCache::Ancestry::count() const
     return shapes.Extent();
 }
 
+bool TopoShapeCache::Ancestry::empty() const
+{
+    return shapes.IsEmpty();
+}
 
 TopoShapeCache::TopoShapeCache(const TopoDS_Shape& tds)
     : shape(tds.Located(TopLoc_Location()))

src/Mod/Part/App/TopoShapeCache.h

@@ -114,6 +114,7 @@ public:
         int find(const TopoDS_Shape& parent, const TopoDS_Shape& subShape);
         TopoDS_Shape find(const TopoDS_Shape& parent, int index);
         int count() const;
+        bool empty() const;
 
         friend TopoShapeCache;
     };

src/Mod/Part/App/TopoShapeExpansion.cpp

@@ -860,7 +860,7 @@ void TopoShape::mapSubElementForShape(const TopoShape& other, const char* op)
     for (auto type : types) {
         auto& shapeMap = _cache->getAncestry(type);
         auto& otherMap = other._cache->getAncestry(type);
-        if ((shapeMap.count() == 0) || (otherMap.count() == 0)) {
+        if ((shapeMap.empty()) || (otherMap.empty())) {
             continue;
         }
 
@@ -1450,7 +1450,7 @@ TopoShape& TopoShape::makeShapeWithElementMap(const TopoDS_Shape& shape,
                 continue;
             }
             auto& otherMap = incomingShape._cache->getAncestry(info.type);
-            if (otherMap.count() == 0) {
+            if (otherMap.empty()) {
                 continue;
             }
             for (int i = 1; i <= otherMap.count(); i++) {

src/Mod/Part/Gui/TaskAttacher.cpp

@@ -952,7 +952,7 @@ void TaskAttacher::updateListOfModes()
     //first up, remember currently selected mode.
     eMapMode curMode = mmDeactivated;
     auto sel = ui->listOfModes->selectedItems();
-    if (sel.count() > 0)
+    if (!sel.isEmpty())
         curMode = modesInList[ui->listOfModes->row(sel[0])];
 
     //obtain list of available modes:
@@ -1054,7 +1054,7 @@ void TaskAttacher::selectMapMode(eMapMode mmode) {
 Attacher::eMapMode TaskAttacher::getActiveMapMode()
 {
     auto sel = ui->listOfModes->selectedItems();
-    if (sel.count() > 0)
+    if (!sel.isEmpty())
         return modesInList[ui->listOfModes->row(sel[0])];
     else {
         if (this->lastSuggestResult.message == SuggestResult::srOK)