Today I once again was hit by a simple question: when are two double (or float) values equal?

Programmers tend to tell each other war stories, i.e. stories of a special one of their never-ending fights against complexity. Here is one I can share with the hope that co-programmers in similar situtations might learn something.

Today I started reading a book about old and new Design Patterns which I brought from my latest visit to the local library, and stumbled over some bad piece of Java code.

Wrapping a collection without exporting any modifying methods should make an immutable object. Or not?