Re: [Boost-bugs] [Boost C++ Libraries] #7730: Generic specializations of is_nullary for custom terminals are not possible

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7730: Generic specializations of is_nullary for custom terminals are not possible
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-02-22 11:15:27

#7730: Generic specializations of is_nullary for custom terminals are not possible
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  Reporter:  andysem           |      Owner:  theller
      Type:  Bugs              |     Status:  new
 Milestone:  To Be Determined  |  Component:  phoenix
   Version:  Boost 1.52.0      |   Severity:  Problem
Resolution:                    |   Keywords:
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Comment (by John Fletcher <J.P.Fletcher@…>):

 Andy

 The only code which will break with this change, as far as I can see, is
 code which has a specialization of the custom terminal. I have just fixed
 that for Boost Spirit. The only change needed was to add the typedef.  I
 don't think there are going to be many of those around, but I have
 modified the entry in ChangeLog to be clearer.

 I intend to make the documentation clear as I get into that side of
 things.

 I have come to the conclusion that the client specialization does not need
 to use the BOOST_PHOENIX_NO_SPECIALIZE_CUSTOM_TERMINAL as the extra
 typedef is all there is. I intend to check that out, as I understand the
 reluctance of maintainers of other libraries to have such things in their
 code.

 I will look into #9693 when I get a chance. I have decided to port the
 proto tool display_expr inot phoenix to have a diagnostic tool. I have the
 basics working but need to do more on the tags to get sensible output.
 When I have that I will be able to dig into phoenix better.  John

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7730#comment:15>
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