Lazy initialization with singleton pattern

Question

Would the following code facilitate lazy initialization?
Or would the singletonInstance be created as soon as somebody includes the header

Answer 1

This is known as the Meyers singleton and they are lazy instantiated.

There are some considerations:

• the singletons will be destroyed at the end of the program in the reverse order in which they are created, so there can be dependency issues.
• C++03 doesn't guarantee against race conditions in multithreaded environments.