The generated code now compiles on 64 and 32 bits platforms without a need for modifications. A fix was introduced for this since developing on 64 bit platforms and regenerating wxWidgets headers xml reference using gccxml translated size_t into unsigned long int on function arguments, while on 32 bits the declaration needed was unsigned int.
The generator was changed to replace unsigned long int declarations to size_t correctly fixing the compilation issue for each platform.
The only change needed now to compile on windows is documented on the Building wxPHP on windows section.
