overloaded based on constness
class val_class {
public:
    val_class(const BigClass &v)
        : _val(v) {}

    const BigClass& val() const {return _val;}
    BigClass& val() {return _val;}
};

void example(const BigClass *pbc, BigClass &rbc)
{
    pbc->val();
    rbc.val();
}

void example(const val_class *pbc, val_class &rbc)
{
    pbc->val();
    rbc.val();
}