Static constructor in c++ and fatal error LNK1120: 1 unresolved externals

Question

To start with i should probably let you know that i am by no means a programmer, and i\'m just doing this for a homework assignment, so if it\'s possible i will require a really

Answer 1

The problem is that Nod::ctr is only declared but not defined.

class Nod
{
    // Declare the counter variable
    static counter ctr;

    ...
};

// Define the counter variable
counter Nod::ctr;

The definition should of course be in a source file, not a header file, or you will get multiple definition errors instead.