静态类模板实例作为成员导致未解决的外部符号错误

Question

I have a template class for a stack (on which I can perform push/pop operations).

If I call the doSomething() function via

A::doSomething();

I get an "unresolved external symbol..." error message. How can I create an static stack in my class a on which I can perform push and pop operations?

class A {
    private:
        // stack which can hold 4 integers
        static stack<int, 4> s;

    public:
        static void doSomething() {
            s.push(4);
        }
};

You can see a code snippet here: codeshare.io/arJmmY

Answer 1

With

class A {
   private:
      static stack<int, 4> s;

    // ...
};

you declare the static member s of the class A .

You have also to define it.

You have to add

stack<int, 4> A::s;

after the A body.