Best practice for libraries supporting both Qt4 and Qt5

[Michael Palimaka]

Hi,

Is there an established best practice for libraries to support both Qt4 
and Qt5?

Currently, some libraries such as phonon rename their Qt5 versions, 
permitting full parallel installation and usage (even of development and 
CMake config files).

Other libraries such as attica bump the major library version only with 
no change in development files.

I personally prefer the phonon approach, simply because it makes it so 
easy to work with Qt4 and Qt5 consumers side-by-side.

Any thoughts?

Best regards,
Michael