Re: [Boost-bugs] [Boost C++ Libraries] #5637: use of mpl::print imposes default constructible requirement on argument

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #5637: use of mpl::print imposes default constructible requirement on argument
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-07-18 21:45:45

#5637: use of mpl::print imposes default constructible requirement on argument
-------------------------------+-----------------------
  Reporter:  ramey             |      Owner:  dave
      Type:  Tasks             |     Status:  closed
 Milestone:  To Be Determined  |  Component:  mpl
   Version:  Boost 1.46.1      |   Severity:  Problem
Resolution:  invalid           |   Keywords:  mpl print
-------------------------------+-----------------------

Comment (by pmachata@…):

 Apologies, I was interpreting the output wrong.  Initialization by NULL
 appears to do exactly what we need.

 From what I can figure out from GCC sources, this warning is controlled by
 -Wconversion-null, which has been on by default since it was introduced in
 2010 (4.5.0).  Before that, the warning was emitted as well, keyed to
 -Wconversion, which was off even in -Wall.  From the time it was written
 in 2000 until 2006 (4.1.0), the warning was always emitted and couldn't
 even be turned off.  So after 4.1.0 up until 4.5.0, it's more advantageous
 to use the signed/unsigned comparison (which is on at least in -Wall),
 otherwise the NULL conversion is better.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5637#comment:7>
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