[Boost-users] Re: copy_if

From: Witz (witz_at_[hidden])
Date: 2003-09-13 05:52:12

You can find an implementation of copy_if in Boost Wiki here:

http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?STLAlgorithmExtensions

An extension that i find useful is the following:

template<class II, class OI, class PRED>
std::pair<II,OI> copy_if(II ibegin, II iend, OI obegin, OI oend, PRED p)
{
        for(; ibegin != iend; ++ibegin)
        {
                if(p(*ibegin))
                {
                        *obegin = *ibegin;
                        if(++obegin == oend)
                                break;
                }
        }
        return std::make_pair(ibegin, obegin);		
}

Here we have a finite sized sink. Items are copied from the source if they 
satisfy the condition and if there is room left in the sink. The positions 
reached are returned on termination of the algorithm.

Witz