Re: [boost] [off-topic] why do we not have std::copy_if?

From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2006-03-14 08:10:06

Caleb Epstein wrote:
> I've recently wondered why std::copy doesn't have an analogous
> std::copy_if:
>
> template<class InIt, class OutIt, class Pr>
>     OutIt *copy_if*(InIt first, InIt last, OutIt dest, Pr pred);
>
>
> that would copy elements to dest where the predicate returns true.
> Not unlike "grep" in Perl and "filter" in Python.
>
> The same goal can be achieved with std::remove_copy_if and the use of
> a sense-reversed predicate, but this leads to confusing code IMHO.
>
> Why wouldn't this be part of the Standard Library, or am I missing
> something ridiculously obvious?

IIRC, in previous discussions of this topic, the consensus was that it was 
an oversight. Josuttis mentions the lack of this algorithm, directing 
readers to use remove_copy_if.

Jeff Flinn