Use smart pointer

src/gui/value/symbol.cpp

@@ -116,6 +116,6 @@ void SymbolValueEditor::editSymbol() {
   wnd->Show();
 }
 
-ValueActionPerformer* SymbolValueEditor::getActionPerformer() {
-  return new ValueActionPerformer(valueP(), editor().getCard(), editor().getSetForActions());
+unique_ptr<ValueActionPerformer> SymbolValueEditor::getActionPerformer() {
+  return make_unique<ValueActionPerformer>(valueP(), editor().getCard(), editor().getSetForActions());
 }

src/gui/value/symbol.hpp

@@ -35,7 +35,7 @@ private:
   /// Show the symbol editor
   void editSymbol();
   /// Get an object to perform actions for us
-  ValueActionPerformer* getActionPerformer();
+  unique_ptr<ValueActionPerformer> getActionPerformer();
   
   // button, or -1 for mouse down, but not on button, or -2 for mouse not down
   int button_down;