[PROJ] Use of EPSG codes in proj_create()

[Oliver Eichler]

> 
> PROJ master (future 6.1.0) has a new proj_normalize_for_visualization()
> function that takes a pedantic-axis-order compliant PJ object (returned 
> by
> proj_create_crs_to_crs()) and add the needed axis swapping to get the
> traditional GIS friendly order.

sounds promising. Will there be an example in the migration guide? Right 
now this guide is pretty frustrating. It gives you a rough example of 
something that does not even match the old behavior and the rest is 
"find out yourself". No documentation in the headers. No obvious link to 
API documentation on the web page. Yes, I found it by chance using 
Google. I don't want to complain too much, but so far the migration is 
more a PITA than anything else.

It would really help to have example code to restore the old complex 
functions like pj_transform(). Keep in mind that you introduced quite 
some pitfalls that will break the software using PROJ silently. The 
moment a user uses a CRS that does it different the software will fail 
leading to a bug report, a lot of investigation why it breaks, the 
realization that new PROJ introduced inconsistencies (from the user's 
point of view) and finally patching the software that uses PROJ over and 
over again. This will be a very frustrating experience for every party 
involved.

Would that be possible?

Oliver