Re: removing from set - does it have to be so ugly?

From:

Vidar Hasfjord <vattilah-groups@yahoo.co.uk>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 25 Nov 2009 08:15:34 CST

Message-ID:

<d907bbc8-e933-4f00-8d61-853d530fc6f2@w19g2000yqk.googlegroups.com>

On Nov 12, 8:47 am, Alfons <alfonsvanwor...@gmail.com> wrote:

std::set<Stuff>::iterator current_item( stuff_set.begin() );
while ( current_item != stuff_set.end() )
{
        if ( is_bad( *item ) )
        {
                std::set<Stuff>::iterator previous_item( --current_item );
                stuff_set.erase( ++current_item );
                current_item = previous_item;
        }
        ++current_item;

}

Is this the best way I can structure this? I hate writing code like
this :(

Consider a non-mutating solution:

    set <Stuff> t;
    remove_copy_if (stuff_set.begin (), stuff_set.end (),
        inserter (t, t.end ()), is_bad);
    swap (t, stuff_set);

If the number of erased elements is high and the cost of copying is
low then it may be more efficient to build a new set than to mutate
the source.

Regards,
Vidar Hasfjord

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