[PROJ] Way to transform coordinates given an osgeo::proj::operation::CoordinateOperation?

[Martin Desruisseaux]

Le 09/10/2019 à 16:19, Even Rouault a écrit :
> You have indeed to go to the C API, but use proj_create() instead of 
> pj_create_internal() 

Thanks. But looking at proj_create() source code, it seems to fetch its 
own DatabaseContext (or maybe not, depending on PROJ string content). 
Can I assume that the PROJ string will be such as proj_create() will not 
need to fetch a DatabaseContext? Or alternatively is there a public API 
for associating a DatabaseContext to a PJ_CONTEXT (if this is not a 
wrong thing to do)?

If understand that a PJ object can be used by only one thread at a time. 
But does PJ retains a reference to PJ_CONTEXT or DatabaseContext after 
construction? In the later case, the requirement would be a little bit 
stronger since I must ensure that no PJ constructed with the same 
PJ_CONTEXT are used in same time, right?

     Martin