.net 4.0 Code Contracts. When to use? When are they a waste of time?

Question

I have been studying .NET 4.0 Code Contracts and looking on stackoverflow as well at question regarding this.

I still have never come across any sample code that use

Answer 1

there is field of study on contracts: http://en.wikipedia.org/wiki/Design_by_contract it was long before they were introduced in .net.

Code contracts are useful to give answers to following questions:

• What does method expect?
• What does method guarantee?
• What does method maintain?

If you can write small and readable contract for those questions then use it.