Method operator()

src/ifcparse/IfcEntityInstanceData.cpp:10–10

    typedef int result_type;

    int operator()(const Blank& /*i*/) const { return -1; }
    int operator()(const Derived& /*i*/) const { return -1; }
    int operator()(const int& /*i*/) const { return -1; }
    int operator()(const bool& /*i*/) const { return -1; }