Re: [Boost-users] circular_buffer, debug and invalid iterator checking

Subject: Re: [Boost-users] circular_buffer, debug and invalid iterator checking
From: Anthony Foglia (AFoglia_at_[hidden])
Date: 2010-11-17 16:40:45

Still working on my circular_buffer iterator invalidation problems, and 
another issue arose.  As I mentioned before my class is roughly

class MyContainer {
   private:
     circular_buffer<T> my_buffer;
     vector<circular_buffer<T>::const_iterator> my_range_ends;
   // omitted
}

I'm trying to add a swap method, and the obvious approach does not work:

void MyContainter::swap(MyContainer & other) {
     using std::swap;
     swap(my_buffer, other.my_buffer);
     swap(my_range_ends, other.my_range_ends);
}

This is unsurprising, because of the iterator invalidation rules.  So 
I'll need to manually figure out the distances and create temporary 
vectors to hold my_range_ends.  But this just seems like too much 
trouble if I'm not in debug mode.  If the BOOST_CB_ENABLE_DEBUG macro 
hadn't been undefined by circular_buffer.hpp I could wrap my hand-coded 
iterator swapping in #if...#endif, and otherwise just use std::swap.

I think this is a valid use case for leaving that macro defined.  Any 
reasons I should not file a ticket requesting the change?

-- 
Anthony Foglia
Princeton Consultants
[phone] x233