Thorsten Ottosen wrote:
John Maddock wrote:
Weapon Liu wrote:
I personally very like this fancy facility, and that's why I present these mumbles here to annoy you guys( if so, my apologies go here:-)) Any comments?
I can give you one use I have for tuples:
I've also used tuples in place of struct's whenever I have an API that needs to return more than 2 items. For example I have some root finding algorithms that accept a unary functor whose root is to be found: the functor returns a tuple containing the function evaluation, plus the first two derivatives. Using a tuple here simplified both implementation and documentation.
I have used tuples in a similar manner, but I kinda think its not the best to do; a named tuple would be more appropriate, or maybe just a struct.
What bothers me is the self-explanatory properties are lost; I can't figure out what tuple element that means what by just looking at the code. Is it
tie(eval,dev1,dev2) = find_root(...)
or
tie(dev1,dev2,eval) = find_root(...)
?
Instead a struct would be somewhat unambiguous:
template< class Float > struct root_result { Float eval, dev1, dev2; };
root_result<float> r = find_root( ... );
You can probably use a fusion map if you want the elements named. Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net