Question

Is there some utility which would allow me to inspect template instantiation?
my compiler is g++ or Intel.

Specific points I would like:

• Step by step instantiation.
• Instantiation backtrace (can hack this by crashing compiler. Better method?)
• Inspection of template parameters.

@gf helpd me with simple type printing, C++ template name pretty print.

However I am getting into boost phoenix and template level makes it very hard to understand what is going on and I would like intelligent solution

also, if you have some techniques inspecting template instantiation, can you please share them.

Thanks

Answer 1

With templates we simply don’t have clean output facilities and there are no compilers i know of that allow you to directly view template instantiations. The closest i found regarding metaprogram debugging was a paper on Templight.

For now the best utilities seem to be:

• static asserts & concept checks (clearly assert your assumptions)
• the mentioned instantiation backtraces (e.g. by using static asserts)
• letting instantiations generate warnings (boost::mpl::print might do it)
• a tracer, a custom class that gets passed as a template argument and is used to emit runtime output (introduced by C++ Templates – The Complete Guide)