How to initialize private static members in C++?

Question

What is the best way to initialize a private, static data member in C++? I tried this in my header file, but it gives me weird linker errors:

class foo
{
           


        

Answer 1

What about a set_default() method?

class foo
{
    public:
        static void set_default(int);
    private:
        static int i;
};

void foo::set_default(int x) {
    i = x;
}

We would only have to use the set_default(int x) method and our static variable would be initialized.

This would not be in disagreement with the rest of the comments, actually it follows the same principle of initializing the variable in a global scope, but by using this method we make it explicit (and easy to see-understand) instead of having the definition of the variable hanging there.