The current library version API is not useful enough to support clients that are compatible with multiple library versions. Ticket #172 covers removing structVersion fields (and links to discussion about why they aren't very usefull in practice).

Ross proposed a global version number API here, but it wasn't really discussed in detail
http://music.columbia.edu/pipermail/portaudio/2008-February/008332.html

void Pa_GetVersion( int *major, int *minor, int *point );

There is also a request to provide #defines in the header file (PA_LIBRARY_VERSION_MAJOR, etc) so that code can detect the version at compile time.

More discussion here:
http://music.columbia.edu/pipermail/portaudio/2008-February/008340.html

Richard Ash wrote:
> We can drop the int Pa_GetVersion(void) function altogether
> (can't think of a use for it,
> programs shoudl check API version not implementation version)."