C++ different singleton implementations

Question

I usually implement the singleton pattern this way :

class Singleton
{
    public:
        virtual ~Singleton() {}

        static Singleton& GetInstance         


        

Answer 1

One important difference between the two is that the creation of the instance in the second example is thread-safe.

You're absolutely right though, the constructor should be private.

Here's a related question: https://stackoverflow.com/a/10479084/1158895