When creating e.g. a new Qt Widgets application in Qt Creator, the .pro file contains the following block:
The Qt documentation here says:
Since Qt 5.13, this macro has no effect. In Qt 5.12 and before, if this macro is defined, the compiler will generate warnings if any API declared as deprecated by Qt is used.
The templates are misleading here, because they guide a user into using a deprecated define. This is especially confusing for those who want to play around with the new deprecations in Qt 5.15.