Hi Szymon, On 16 November 2011 10:40, Szymon Gatner <szymon.gatner@gmail.com> wrote:

I realize this is not really a multi-index bug but after I updated from 1.47 to 1.48 my code no longer compiles due to this code:

template<typename SuperMeta,typename TagList> inline boost::mpl::true_* boost_foreach_is_noncopyable( boost::multi_index::detail::sequenced_index<SuperMeta,TagList>*&, boost::foreach::tag) { return 0; }

...snip...

this happens because as suggested in boost.foreach docs I have this earlier:

#define foreach BOOST_FOREACH

I'm not certain whether there's anything under-the-hood of multi_index that could do this, but since #define foreach BOOST_FOREACH was just an example, and the user could define any PP token to expand as such, a change to multi_index could only ever work around that one example. I see a couple of possibilities for you: either #undef foreach before the above code, then #define it again afterwards, or use a name other than 'foreach'. Unfortunately (or not) this is just the way PP macros work, and why avoiding them is desirable - they are not namespaceable unlike real types & names. --rob -- Rob Desbois Eml: rob.desbois@gmail.com Blog: http://theotherbranch.wordpress.com/ Tel: 07946 705987 "I disapprove of what you say, but I’ll defend to the death your right to say it", Voltaire

Szymon Gatner wrote:

this happens because as suggested in boost.foreach docs I have this earlier:

#define foreach         BOOST_FOREACH

which (if I understand correctly) causes offending line to expand into:

boost::BOOST_FOREACH::tag

Is there anything easy I could do to fix this?

Your problem depends on the ordering of header files and the macro definition: // OK #define foreach BOOST_FOREACH #include <boost/foreach.hpp> #include <boost/multi_index/hashed_index.hpp> // OK #include <boost/foreach.hpp> #include <boost/multi_index/hashed_index.hpp> #define foreach BOOST_FOREACH // Error #include <boost/foreach.hpp> #define foreach BOOST_FOREACH #include <boost/multi_index/hashed_index.hpp> If you can control the ordering, you can avoid the problem. But this solution is error prone. Fortunately, is_noncopyable and is_lightweight_proxy customization points seem to be only used in Boost.MultiIndex. So, I think, changing the name of namespace foreach is a viable solution. (Please note that this solution can break existing codes using is_noncopyable and is_lightweight_proxy customization points.) 1. Change namespace foreach --> namespace foreach_ foreach:: --> foreach_:: in boost/foreach.hpp and boost/foreach_fwd.hpp. 2. Change foreach:: --> foreach_:: in boost/multi_index/hashed_index.hpp boost/multi_index/ordered_index.hpp boost/multi_index/random_access_index.hpp boost/multi_index/sequenced_index.hpp (and, if you want, libs/foreach/test/noncopyable.cpp). Regards, Michel

Szymon Gatner <szymon.gatner <at> gmail.com> writes:

Hi,

I realize this is not really a multi-index bug but after I updated from 1.47 to 1.48 my code no longer compiles due to this code:

[...]

btw, 1.47 version has no explicit section marked as

/* Boost.Foreach compatibility */

yet I used BOOST_FOREACH macro on many indices all over the place.

This bit was included in Boost 1.48 for reasons explained at https://svn.boost.org/trac/boost/ticket/5741 I think it is extremely unfortunate that Boost.Foreach advises people to #define foreach when this is an internal name of the library. Sorry about this, I don't think I can do anything to solve it from Boost.MultiIndex. Joaquín M López Muñoz Telefónica Digital