C++ singleton vs. global static object

Question

A friend of mine today asked me why should he prefer use of singleton over global static object? The way I started it to explain was that the singleton can have state vs. s

Answer 1

Another benefit of the Singleton over the global static object is that because the constructor is private, there is a very clear, compiler enforced directive saying "There can only be one".

In comparison, with the global static object, there will be nothing stopping a developer writing code that creates an additional instance of this object.

The benefit of the extra constraint is that you have a guarantee as to how the object will be used.