xxxInPlace or xxxCopy?

[Jonathan M Davis]

On Thursday 20 January 2011 03:51:48 Trass3r wrote:
> If such an annotation was introduced, it should be the other way around.
> But imo discarding a return value should always result in a warning,
> the function returns something for a reason.

Actually, there are plenty of cases where you throw away the return value. A 
number of overloaded operators are prime examples - such as opAssign. 
std.algorithm.sort both sorts in place _and_ returns a sorted range (so that 
other algorithms can then know that the range is sorted). It's really quite easy 
to get legitimate cases where throwing away the return value makes perfect 
sense. Now, if you're dealing with a strongly pure function which throws away 
its return value, then yes, that's definitely bug, since the only effect of the 
function is its return value. Frequently however, that's not the case.

Yes, you can have bugs because you didn't actually use the return value of a 
function, but it's that necessarily uncommon to have function calls which 
legitimately throw away their return value.

- Jonathan M Davis