Oop singleton

=== global variable ===
:http://www.blackwasp.co.uk/gofpatterns.aspx Singleton. The singleton pattern ensures that only one object of a particular class is ever created. All further references to objects of the singleton class refer to the same underlying instance.
you have a global variable , the references are the pointers that the all the functions have to this instance as their
first paramater. Any function can change the instance variables(struct).
=== links ===
https://testing.googleblog.com/2008/08/root-cause-of-singletons.html , 
 
http://misko.hevery.com/2008/08/17/singletons-are-pathological-liars/ , 
 
http://misko.hevery.com/2008/08/21/where-have-all-the-singletons-gone/
https://matt.berther.io/
https://blogs.msdn.microsoft.com/scottdensmore/2004/05/25/why-singletons-are-evil/
http://www.davidtanzer.net/6_reasons_why_you_should_avoid_singletons
=== links ===
Oop
Category:Oop