Re: [Discuss-gnuradio] SWIG/C++ Template Expansion Info

[Eric Blossom]

On Wed, Aug 29, 2007 at 10:48:07PM -0400, Michael Dickens wrote:
> I've always wondered why GNU Radio didn't use C++ templates for gr- 
> blocks (see e.g. the 'gengen' subdirectory in gnuradio-core), since  
> they generally result in much less written code.  Might partly be  
> that SWIG only "recently" (as of 1.3.12 or so) added C++ templates to  
> its bag of tricks?  Also might be that the SWIG interface is  
> challenging at its best, let alone with something as complex as C++  
> template expansion / instantiation?
> 
> Last week I hacked through both the C++ and SWIG necessities to get  
> template C++ gr-blocks to expand (instantiate) correctly into shared  
> libraries that work correctly with both Python and C++.  After much  
> fussing, I wrote a SWIG macro (%define), similar to  
> "GR_SWIG_BLOCK_MAGIC", but for template C++ class expansion into  
> uniquely named GR blocks.  While the macro might not work for  
> everyone (or it might, testers would be appreciated), and maybe it's  
> a bit ugly to read, the steps in it make sense according to the SWIG  
> documentation.
> 
> If anyone is interested I can provide more information. - MLD

Great!

Can you point us to the code, and show for example, how you'd handle
gr_sig_source*?

Thanks,
Eric