Question: Is it possible to initialize a static const member of my class during run-time? This variable is a constant throughout my program but I want to send it as a command-line argument. 

```
//A.h
class A {
public: 
    static const int T;
};

//in main method
int main(int argc,char** argv)
{
    //how can I do something like 
    A::T = atoi(argv[1]);
}

```

If this cannot be done, what is the type of variable I should use? I need to initialize it at run-time as well as preserve the constant property.

Answer: 
There is a trick, but you should probably avoid it! Here's a bare bones example to illustrate the principle:

```
int const& foo(int i) {
    static const int j = (i == 0 ? throw 0 : i); 
    return j; 
}

int main() {
    try { 
        int x = foo(0); // oops, we throw        
    } catch(...) {}

    int x = foo(1); // initialized..
    int y = foo(0); // still works..     
}

```

Careful!
Use a Singleton Pattern here.
have a data member which you'd like to initialize at run time in the singleton class. One a single instance is created and the data member is properly initialized, there would be no further risk of overwriting it and altering it.

Singleton would preserve the singularity of your data.

Hope this helps.