Re: [Boost-users] FOREACH with maps

From: Dave Steffen (dgsteffen_at_[hidden])
Date: 2005-05-10 17:52:34

Thanks very much for all your replies.

I wrote
> However, for maps, the second variation (declaring outside the macro)
> doesn't work:
>
> map<int,int> m;
> ...
> FOREACH (map<int,int>::value_type i, m) {...}  // compiles
> map<int,int>::value_type i;
> FOREACH (i, m) {...}                     // COMPILE ERROR
>

And the various replies are right on the money, and appreciated.  I
thought it was something like this, but I couldn't quite figure out
what was going on.

If anyone's interested: I'm playing with the idea of extending FOREACH
in a way so that, instead of having a pair<>, you've got two separate
variables for key and value.  Maybe something like:

map<int,int> m;
...
FOREACH_PAIR(int key, int value, m)
{ ... }

I'm having a very moderate amount of success.  Anyone else playing
with this sort of thing?

Thanks again!

----------------------------------------------------------------------
Dave Steffen, Ph.D.       "The only justification for our concepts and 
Software Engineer IV       systems of concepts is that they serve to 
Numerica Corporation       represent the complex of our experiences;
ph [phone] x27      beyond this they have no legitimacy."
fax [phone]              -- Albert Einstein
dgsteffen_at_[hidden]