Some questions in Qt's Source Code

[jpn]

1. An explicit constructor makes sure no such statement (implicit conversion) is accepted:

QWidget widget = new QWidget;

QWidget widget = new QWidget;

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Otherwise compiler would accept the above statement because QWidget has a constructor that takes QWidget* (parent).

2. Take a look at QPointer docs. QPointer is a helper class that provides a guarded pointer.

3. See our wiki: Private implementation.

4. Many macros in Qt are just markers for meta-object compiler. That's why many of them are defined as empty.