Re: [Boost-users] Tuple use/overuse?

From: Zeljko Vrba (zvrba_at_[hidden])
Date: 2007-07-26 01:46:11

On Thu, Jul 26, 2007 at 11:16:08AM +1200, Richard Dingwall wrote:
> 
> Pardon me if it's just a two-dimensional example for simplicity, but why not
> use std::pair?
> 
Orthogonality.  Personally, I'd find it very cumbersome to make an
exception for pairs and write t.first, t.second when I write t.get<N>()
for larger tuples.  Plus, if the tuple should grow at some point,
you'd have to fix all occurences of .first and .second.

However, I have another question regarding tuples:  the debugger expands
tuple<X1,X2,X3> to tuple<X1,X2,X3,null_type,null_type,...> [a large list
of null_types in the template].  Do these null_types take space in the
tuple, and do they slow down passing by value (due to unneccessary
copying of null_type)?