[C++-sig] Re: My latest project

[Neal D. Becker]

> 
>>> I have only 2 quick comments in this one:
>>> 
>>> 1. You should never use std::[binary|unary]_function because it
>>>    suppresses EBO.  Consider what happens when you have a
>>>    compressed_pair<minus<int>,plus<int> >.
>>
>> OK.  I assume this means "Empty Base Optimization?"
> 
> Yep.
> 

Why is this important?  Is this comment just made as a general principle, or
does it relate to the actual use in the vector arithmetic I wrote?  I
assume the only signficance of EBO is a size issue, in which case it
wouldn't matter in the way I used it for vector arithmetic.  Or, is there
something I'm missing?  (I went ahead and made the change you suggested
anyway, but I'm curious).