Singleton: How should it be used

Question

Edit: From another question I provided an answer that has links to a lot of questions/answers about singletons: More info about singletons here:

So I have read th

Answer 1

Answer:

Use a Singleton if:

• You need to have one and only one object of a type in system

Do not use a Singleton if:

• You want to save memory
• You want to try something new
• You want to show off how much you know
• Because everyone else is doing it (See cargo cult programmer in wikipedia)
• In user interface widgets
• It is supposed to be a cache
• In strings
• In Sessions
• I can go all day long

How to create the best singleton:

• The smaller, the better. I am a minimalist
• Make sure it is thread safe
• Make sure it is never null
• Make sure it is created only once
• Lazy or system initialization? Up to your requirements
• Sometimes the OS or the JVM creates singletons for you (e.g. in Java every class definition is a singleton)
• Provide a destructor or somehow figure out how to dispose resources
• Use little memory