MISRA Discussion Forums

Do these rules apply to class members?

If so, do they apply to instances of template class members?

Code:
template

class C {

    T member1; // never used; compliant with 0-1-3?

    T member2; // C::member2 is used but C::member2 is not; compliant with 0-1-3?

    typedef T Unused; // typedef never used: non-compliant with 0-1-5.

    typedef T X; // C::X is used but C::X is not; compliant with 0-1-5?

    void call() { // only instantiated for C

       use(static_cast(member2));

    }

};

int main() {

  C().call();

  C();

}

The same question also applies to 0-1-4.

For 0-1-10 the situation is different, as class template member functions only get instantiated if they actually used. Thus C::call() is compliant with 0-1-10. A completely unused class template member function would be non-compliant with Rule 14-7-1.

The basic answer to all these queries is that every definition in the program must be used somewhere, or conversely, it should not be possible to remove a definition from the code and still have the program compile.

So for a template class, each member of the class must be used by at least one instantiation of the template.

grunwald

misra cpp