Re: base classes and inheritance problem

From:

"Alf P. Steinbach" <alfps@start.no>

Newsgroups:

comp.lang.c++

Date:

Sun, 16 Mar 2008 10:05:51 +0100

Message-ID:

<13tpojm5svofq21@corp.supernews.com>

* zionztp@gmail.com:

#include <iostream>
using namespace std;

class A
{
    public:
    A(){n=5;}
    virtual void show() = 0;

    protected:
        int n;
};

class B : public A
{
    public:
    void show(){cout << n << endl;}
};

class C : public A
{
    public:
    void show(){cout << n*2 << endl;}
};

int main()
{
    A *c;
    int class_num = 0; //user input

    if(class_num == 0){
        c = new B();
    }else{
        c = new C();
    }

    c->show();

    delete c;
    return 0;
}

Considering this example, what would be the best way if i wanted to
avoid virtual functions? of course i've reconsidered the use of
virtual functions since it may be totally unneeded optimization to
avoid them, but im just curious about this right now, and yes you are
right im not very used to C++ i mainly use it as an "extended" C.

Please don't quote signatures.

Depending on what it is you want to try to achieve...

   int main()
   {
       using namespace std;

       int const userInput = 0;
       cout << (userInput == 0? 5 : 10) << endl;
   }

You might think that answer's facetious. But it's not. If the problem doesn't
call for classes and objects, or templates, whatever..., don't. Use the tools
and abstractions that suit the problem. Give a damn about micro-optimization.
Aim at clarity.

Cheers, & hth.,

- Alf

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