Re: [boost] [pointer_container] ptr_map_iterator::key() gone in 1.34 ?

From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2007-04-03 03:02:24

Paul Rose skrev:
> There seems to be a substantial interface change between 1.33 and 1.34
> of ptr_map.
>  
> I'm trying to move a largeish project from 1.33 to 1.34.  The only
> unsolved problem is that it has 21 separate declarations of a ptr_map,
> each with a dozen or so uses of iterator where *iter has to be replaced
> with *iter->second and iter->key() has  to be replaced with iter->first.
> 
>  
> The 1.34 documentation at http://www.boost-consulting.com/boost/ doesn't
> seem to mention this, and my searches can't seem to turn up where this
> was discussed.  

This is not the proper 1.34 documentation.

> I can see why the new interface might be preferred, but can anybody
> provide a reference to the discussion (or other insight) that led to
> this code-breaking change?

Better interface compatibility with std::map s.t. algorithms etc. can be 
reused.

The standard interface with std::pair might suck, but it is standard.

> Ideally I'd like my code to work with both 1.33 and 1.34.  Any hints on
> how to do this elegantly?

Add your own layer of indirection:

namespace my_namespace
{
   template< class PtrMap >
   typename PtrMap::key_type ptr_map_key( const PtrMap& )
   {
#ifdef BOOST_1_34
..

-Thorsten