why no ++?

[Tim Rowe]

In article <3B6A6B97.2060306 at herts.ac.uk>, m.1.robinson at herts.ac.uk (Mark 
Robinson) wrote:

> I guess it is perhaps not as clear, but I am not aware of it being a
> common cause of errors in C++ or java (doesn't mean it isn't, just that
> I am not aware of them). I also miss +=, *=, %=, /=, would it really 
> make the code that much harder to read/maintain?

It certainly is /a/ source of bugs in C++, and I would expect in Java too. 
One infamous one is constructs of the form min(a++, b++).

If min is a function and a and b are distinct, each is incremented once 
and the smaller is returned -- probably what is expected.

If min is a function and b is an alias for a then it is incremented twice 
and returned. Probably a bug.

If min is a preprocessor macro, it probably expands to something like
(a++)<(b++)?(a++):(b++); now if a and b are distinct both are incremented, 
the lesser is returned and is then incremented again -- the value returned 
is probably now the value of neither a /nor/ b. If that is intended 
behaviour then I hope I never have to maintain your code!

If min is a preprocessor macro and b is an alias for a then it is 
incremented twice, returned, then incremented again. Sheesh!

In short, side effects are a Bad Thing!