On 01/13/2012 03:20 PM, Neil Cerutti wrote:
They perform the same action, but their semantics are different. operator+ will always return a new object, thanks to its signature, and operator+= shall never do so. That's the main difference I was getting at.
I was talking about the combination of + and =, since the discussion is about 'a = a + b' vs 'a += b', not 'a + b' vs 'a += b' (where the differences are obvious).
And I stand by my statement. In 'a = a + b', operator+ obviously returns a new object, but operator= should then go and assign the result to and return a reference to 'a', just like how 'a += b' will return a reference to 'a'.
If you're working in C++ and overload your operators so that 'a += b' and 'a = a + b' have different observable behaviors (besides perhaps time), then either your implementation is buggy or your design is very bad-mannered.
Evan -- http://mail.python.org/mailman/listinfo/python-list
