Cleanup QtWidgets examples: - use nullptr (clang-tidy) - use member-initialization - adjust the style - fix includes Change-Id: Ic5448606aacc525ea60b615a69227017aa2b821a Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Task-number: QTBUG-59249 Change-Id: I71f1d2e28f0cadbad1d6bcf117198018eaf8e012 Reviewed-by: Topi Reiniö <topi.reinio@qt.io>