[boost] [1.56.0 b1] Issue with mpl/is_convertable/asio

Subject: [boost] [1.56.0 b1] Issue with mpl/is_convertable/asio
From: Thomas Suckow (thomas.suckow_at_[hidden])
Date: 2014-07-28 19:55:51

In testing '1.56.0 Beta 1' I have found that I am unable to compile https://github.com/splunk/pion on RHEL6_x64
Pion compiles fine with 1.55.0

I suspect the recurring "anonymous enum" is the kicker, though I am not sure where to even begin in diagnosing this.
error: ‘const boost::asio::detail::buffer_sequence_adapter_base::<anonymous enum>&’ is/uses anonymous type
error: no type named ‘type’ in ‘struct boost::is_convertible<const boost::asio::detail::buffer_sequence_adapter_base::<anonymous enum>&, const boost::iterator_range_detail::iterator_range_tag&>’
error: ‘value’ is not a member of ‘boost::mpl::aux::nested_type_wknd<boost::is_convertible<const boost::asio::detail::buffer_sequence_adapter_base::<anonymous enum>&, const boost::iterator_range_detail::iterator_range_tag&> >’

Full error log:
http://pastebin.com/yeScQCpx

If I get a chance I will see if I can reproduce this on a more modern compiler.

Any assistance in correcting this before the 1.56.0 release would be appreciated.
It also may or may not be related to http://thread.gmane.org/gmane.comp.lib.boost.devel/253259/focus=253261

Regards,
Thomas