Re: [Boost-bugs] [Boost C++ Libraries] #6760: PUSH_BACK/_FRONT on empty array broken

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #6760: PUSH_BACK/_FRONT on empty array broken
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-04-03 20:11:13

#6760: PUSH_BACK/_FRONT on empty array broken
------------------------------------+---------------------------------------
  Reporter:  yves.pausch@…          |       Owner:  no-maintainer
      Type:  Bugs                   |      Status:  new          
 Milestone:  Boost 1.50.0           |   Component:  preprocessor 
   Version:  Boost 1.49.0           |    Severity:  Problem      
Resolution:                         |    Keywords:               
------------------------------------+---------------------------------------

Comment (by pmenso57):

 There is no such thing as a zero-element array or tuple.

 {{{
 (0, ())
 }}}

 should be

 {{{
 (1, ())
 }}}

 because it is a one-element array whose element is nothing--just as with

 {{{
 (2, (,))
 (3, (,,))
 }}}

 and so on.

 If there was a zero-element array, it would be something like:

 {{{
 (0, ~) // (0,) in >= C99 or >= C++11
 }}}

 but that rogue value would require special handling in all of the array
 operations that defer to tuple operations.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6760#comment:1>
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