Book Image

Mastering Qt 5 - Second Edition

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5 - Second Edition

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.11 is an app development framework that provides a great user experience and develops full capability applications with Qt Widgets, QML, and even Qt 3D. Whether you're building GUI prototypes or fully-fledged cross-platform GUI applications with a native look and feel, Mastering Qt 5 is your fastest, easiest, and most powerful solution. This book addresses various challenges and teaches you to successfully develop cross-platform applications using the Qt framework, with the help of well-organized projects. Working through this book, you will gain a better understanding of the Qt framework, as well as the tools required to resolve serious issues, such as linking, debugging, and multithreading. You'll start off your journey by discovering the new Qt 5.11 features, soon followed by exploring different platforms and learning to tame them. In addition to this, you'll interact with a gamepad using Qt Gamepad. Each chapter is a logical step for you to complete in order to master Qt. By the end of this book, you'll have created an application that has been tested and is ready to be shipped.
Table of Contents (16 chapters)

Silencing unused variable warnings

If your compiler is configured to output its warnings, you will probably see the following type of log sometimes:

warning: unused parameter 'myVariable' [-Wunused-parameter] 

This is a safety warning to tell the developer to keep their code clean and to avoid dead variables. It is a good practice to try to minimize this kind of warning. However, sometimes, you have no choice; you override an existing function, and you do not use all of the parameters. You now face a conundrum. On the one hand, you can silence the warning for your whole application, and on the other hand, you can let these safety warnings pile up in your compile output. There must be a better option.

Indeed, you can silence the warning for your function only. There are two ways of doing this, as follows:

  • Using the C/C++ syntax
  • Using a Qt macro

Let's suppose that...