The algorithm is a simple symbol table search in method resolution order.

If the method is not in the symbol table (perhaps it's loaded with AUTOLOAD, or otherwise loaded after the ->can call) it won't be found. If it's loaded via AUTOLOAD, the module itself will need to overload can so it can answer effectively for those functions; this is somewhat tricky to get right, as you need to allow the search to continue further up the tree as necessary.

You mentioned later that ->can is not seeing your C++ functions. Unless these are exposed to the Perl level, they won't be in the symbol table; but then again, you shouldn't be able to call them from Perl, either, so finding them with ->can is simply wrong. If this is the case, you'll need to elaborate more as to what's going on.

In reply to Re: Workings of UNIVERSAL::can by Somni
in thread Workings of UNIVERSAL::can by geoffleach

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