Merge #10498: Use static_cast instead of C-style casts for non-fundamental types

9ad6746ccd Use static_cast instead of C-style casts for non-fundamental types (practicalswift)

Pull request description:

  A C-style cast is equivalent to try casting in the following order:

  1. `const_cast(...)`
  2. `static_cast(...)`
  3. `const_cast(static_cast(...))`
  4. `reinterpret_cast(...)`
  5. `const_cast(reinterpret_cast(...))`

  By using `static_cast<T>(...)` explicitly we avoid the possibility of an unintentional and dangerous `reinterpret_cast`. Furthermore `static_cast<T>(...)` allows for easier grepping of casts.

  For a more thorough discussion, see ["ES.49: If you must use a cast, use a named cast"](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast) in the C++ Core Guidelines (Stroustrup & Sutter).

Tree-SHA512: bd6349b7ea157da93a47b8cf238932af5dff84731374ccfd69b9f732fabdad1f9b1cdfca67497040f14eaa85346391404f4c0495e22c467f26ca883cd2de4d3c

src/qt/bitcoingui.cpp

@@ -599,7 +599,7 @@ void BitcoinGUI::createTrayIconMenu()
 #else
     // Note: On Mac, the dock icon is used to provide the tray's functionality.
     MacDockIconHandler *dockIconHandler = MacDockIconHandler::instance();
-    dockIconHandler->setMainWindow((QMainWindow *)this);
+    dockIconHandler->setMainWindow(static_cast<QMainWindow*>(this));
     trayIconMenu = dockIconHandler->dockMenu();
 #endif
 
@@ -922,13 +922,13 @@ void BitcoinGUI::message(const QString &title, const QString &message, unsigned
             buttons = QMessageBox::Ok;
 
         showNormalIfMinimized();
-        QMessageBox mBox((QMessageBox::Icon)nMBoxIcon, strTitle, message, buttons, this);
+        QMessageBox mBox(static_cast<QMessageBox::Icon>(nMBoxIcon), strTitle, message, buttons, this);
         int r = mBox.exec();
         if (ret != nullptr)
             *ret = r == QMessageBox::Ok;
     }
     else
-        notificator->notify((Notificator::Class)nNotifyIcon, strTitle, message);
+        notificator->notify(static_cast<Notificator::Class>(nNotifyIcon), strTitle, message);
 }
 
 void BitcoinGUI::changeEvent(QEvent *e)