c++ template singleton static pointer initialization in header file

Question

What is wrong with this implementation in header file?

template 
class Singleton
{
public:
    static T* getInstance() 
    {
        if (m         


        

Answer 1

Pointers are being initialized to NULL by standard, why I need to explicitly initialize?

You don't need.

template 
T* Singleton::m_instance;

This will suffice as static & global variables are zero initialized by default

Variables with static storage duration (3.7.1) or thread storage duration (3.7.2) shall be zero-initialized (8.5) before any other initialization takes place.