Fem: modernize C++: return braced init list

src/Mod/Fem/App/FemPostPipelinePyImp.cpp

@@ -37,7 +37,7 @@ using namespace Fem;
 // returns a string which represents the object e.g. when printed in python
 std::string FemPostPipelinePy::representation() const
 {
-    return std::string("<FemPostPipeline object>");
+    return {"<FemPostPipeline object>"};
 }
 
 PyObject* FemPostPipelinePy::read(PyObject *args)

src/Mod/Fem/Gui/PropertyFemMeshItem.cpp

@@ -115,7 +115,7 @@ QVariant PropertyFemMeshItem::value(const App::Property*) const
     out << QObject::tr("Polyhedrons") << ": " << ctH << ", ";
     out << QObject::tr("Groups") << ": " << ctG;
     out << ']';
-    return QVariant(str);
+    return {str};
 }
 
 QVariant PropertyFemMeshItem::toolTip(const App::Property* prop) const
@@ -145,7 +145,7 @@ void PropertyFemMeshItem::setEditorData(QWidget* editor, const QVariant& data) c
 QVariant PropertyFemMeshItem::editorData(QWidget* editor) const
 {
     Q_UNUSED(editor);
-    return QVariant();
+    return {};
 }
 
 int PropertyFemMeshItem::countNodes() const

src/Mod/Fem/Gui/ViewProviderFemConstraint.cpp

@@ -130,7 +130,7 @@ void ViewProviderFemConstraint::setDisplayMode(const char* ModeName)
 
 std::vector<App::DocumentObject*> ViewProviderFemConstraint::claimChildren()const
 {
-    return std::vector<App::DocumentObject*>();
+    return {};
 }
 
 void ViewProviderFemConstraint::setupContextMenu(QMenu *menu, QObject *receiver, const char *member)

src/Mod/Fem/Gui/ViewProviderFemMesh.cpp

@@ -416,7 +416,7 @@ std::string ViewProviderFemMesh::getElement(const SoDetail* detail) const
                 str << "Node" << vertex;
             }
             else {
-                return std::string();
+                return {};
             }
         }
     }
@@ -455,7 +455,7 @@ SoDetail* ViewProviderFemMesh::getDetail(const char* subelement) const
 
 std::vector<Base::Vector3d> ViewProviderFemMesh::getSelectionShape(const char* /*Element*/) const
 {
-    return std::vector<Base::Vector3d>();
+    return {};
 }
 
 std::set<long> ViewProviderFemMesh::getHighlightNodes() const

src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp

@@ -21,7 +21,7 @@ using namespace FemGui;
 // returns a string which represents the object e.g. when printed in python
 std::string ViewProviderFemMeshPy::representation() const
 {
-    return std::string("<ViewProviderFemMesh object>");
+    return {"<ViewProviderFemMesh object>"};
 }
 
 

src/Mod/Fem/Gui/ViewProviderFemPostPipelinePyImp.cpp

@@ -33,7 +33,7 @@ using namespace FemGui;
 // returns a string which represents the object e.g. when printed in python
 std::string ViewProviderFemPostPipelinePy::representation() const
 {
-    return std::string("<ViewProviderFemPostPipeline object>");
+    return {"<ViewProviderFemPostPipeline object>"};
 }
 
 PyObject *ViewProviderFemPostPipelinePy::updateColorBars(PyObject *args)