Question

I have been relying on the misconception that static variables defined in member functions were limited to the specific class instance.

To illustrate my misconception:

#include <iostream>
#include <string>

struct Simple {
    template<typename T>
    T & Test(const T & Value) {
        static T Storage = Value;
        return Storage;
    }
};

int main() {
    Simple A;
    Simple B;

    std::string Foo = A.Test(std::string("Foo"));
    std::string Bar = B.Test(std::string("Bar"));

    std::cout << Foo << ' ' << Bar << std::endl;
}

The behavior I expected would have resulted in the output of

Foo Bar

Is there a simple alternative that would result in the behavior I expected?

Edit

A cutdown version of the class that has the issue:

class SignalManager {
    private:
        template<typename T> struct FunctionPointer { typedef boost::function1<void, const T &> type; };
        template<typename T> struct Array { typedef std::vector<typename FunctionPointer<T>::type> type; };

        template<typename T>
        typename Array<T>::type & GetArray() {
            static typename Array<T>::type Array;
            return Array;
        }

    public:
        template<typename T, typename M>
        void Broadcast(const M & Value) {
            typename Array<T>::type::iterator Iterator;
            for(Iterator = GetArray<T>().begin(); Iterator != GetArray<T>().end(); ++Iterator) {
                (*Iterator)(Value);
            }
        }

        template<typename T, typename F>
        void Connect(const F & Function) {
            GetArray<T>().push_back(Function);
        }
};

Answer 1

If I understand your confusion, the alternative is member variables…

template<typename T>
struct Simple {
    T storage;

    T & Test(const T & Value) {
        storage = Value;
        return Storage;
    }
};