[PROJ] comparing projstrings

[Even Rouault]

Idan,

> 
> Is there any importance for the order of the parameters in a projstring CRS
> definition?

For a single step pipeline, no. But starting with PROJ 5, it you use a 
proj=pipeline, yes the order of steps matter.

> 
> Is there a function that compares projstrings that takes into consideration
> that two projstrings can be equal even if the strings are not exactly the
> same?

For single-step proj strings and currently released versions, using GDAL with 
OSRImportFromProj4() + OSRIsSame() will do

If you use PROJ master, you can equivalently use 
proj_create_from_proj_string() + proj_is_equivalent_to(). Note that this will 
work as you mentionned only for single-step strings. (For multiple steps, this 
will mostly be equivalent to exact string comparisons)

Even

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