[Gdal-dev] SWIG Exceptions for C# Bindings

[Simon Perkins]

Can someone remind me how error reporting works with the GDAL and OGR C# 
bindings? Do errors typically throw exceptions, or return status codes, 
or nulls, or both? There seems to be code to throw exceptions in most of 
the method definitions, but the code in swig/csharp/apps often appears 
to be checking for return null values instead. Which is correct?

For instance, if OGR.DataSource.GetLayerByIndex() is invoked with an 
invalid index, or if something else goes wrong, do we always/sometimes 
get an exception or do we just get a null back? Is there a general policy?

Cheers,

Simon