This warning only show when i attributed the false value.

At windows:
C:\Users\ricardo\Documents\Thorx\workspace\thx6\2\ src\app\main.cpp:88: warning: converting 'false' to pointer type for argument 2 of 'void QQmlContext::setContextProperty(const QString&, QObject*)' [-Wconversion-null]
engine.rootContext()->setContextProperty("QT_DEBUG", false);

At OSX:
/Users/ricardo/Thorx/workspace/thx6/2/src/app/main.cpp:88: warning: initialization of pointer of type 'QObject *' to null from a constant boolean expression [-Wbool-conversion]
engine.rootContext()->setContextProperty("QT_DEBUG", false);

Source code
Qt Code:
  1. QQmlApplicationEngine engine;
  2. #ifdef QT_DEBUG
  3. engine.rootContext()->setContextProperty("QT_DEBUG", true);
  4. #else
  5. engine.rootContext()->setContextProperty("QT_DEBUG", false);
  6. #endif
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Thanks.