How to efficiently bind either an lvalue or rvalue to the same reference?

I'd create separate function, which accept reference and call it, like this:

void func( MyObject const & original ) {
    if (apply_alteration)
        func_internal(alter_obj(original));
    else
        func_internal(original);
}

void func_internal( MyObject const & possibly_altered) {
    // ...
}