Edit File: rubyfragments.swg
/* Create a file with this name, 'rubyfragments.swg', in your working directory and add all the %fragments you want to take precedence over the ones defined by default by swig. For example, if you add: %fragment(SWIG_AsVal_frag(int),"header") { SWIGINTERNINLINE int SWIG_AsVal(int)(VALUE obj, int *val) { <your code here>; } } this will replace the code used to retrieve an integer value for all the typemaps that need it, including: int, std::vector<int>, std::list<std::pair<int,int> >, etc. */