Re: [boost] [new Warnings policy] MS C4180 on the Maintenance Guidelines

Subject: Re: [boost] [new Warnings policy] MS C4180 on the Maintenance Guidelines
From: Zachary Turner (divisortheory_at_[hidden])
Date: 2009-11-18 10:25:12

On Mon, Nov 16, 2009 at 3:08 PM, Patrick Horgan <phorgan1_at_[hidden]> wrote:

>
>
>     Wonderful!
>
>   C4180    Surely instead of suggesting suppressing you would remove the
>   meaningless qualifier?

  C4996   Microsoft deprecated these functions on their own (and they call
>   themselves POSIX compliant), and replaced them with extremely dangerous
>   replacements  that they claim are safe.  The replacement functions are
>   non-POSIX and aren't available from other compilers, hence non-portable.
>   These warnings should be suppressed.  I believe that you can also
> suppress
>   by defining _CRT_NONSTDC_NO_DEPRECATE before and undef'ing after to do a
>   local suppression.
>
Somewhat off topic, but why exactly are these extremely dangerous, and not
secure?

>   C4800 Might suggest that they use a bool valued expression in the first
>   place, i.e. instead of foo, foo!=0, or do a static cast to bool.  This is
> at
>   times indicative of real bugs, when people turn out to not be doing what
>   they thought they were doing.  Apparently this is one of my favorite bugs
>   (by favorite I don't mean that I like it either!)
>   C4506 Might suggest that they provide the definition;)
>   Someone had mentioned a redesign of boost:noncopyable to work around the
>   C4511 and C4512 warnings from deriving from boost:noncopyable.  Is anyone
>   looking into it?  Is it even possible?  It's a shame that this wonderful
>   thing generates so much noise.  If course, if you want to make a class
>   uncopyable, rather than inheriting from boost:uncopyable, you could just
>   make  your  own copy and assignment declarations privately and without
>   definitions if you don't need them.  It makes the class non-copyable
> without
>   generating the warnings.  If you have other causes of C451{0-2} see
> below:
>   C4510/C4511/C4512 In general if you provide one of destructor, assignment
>   operator, and copy constructor, then you need all three.  The best fix is
> to
>   provide the method.  Providing a private declaration is a way of telling
> the
>   compiler that you are sure your case is different--if it really is.
>  These
>   are  all caused by either inaccessible base class version, or const or
>   reference data members.
>   Similar to 4511 and 4512 are the following which occur on trying to
> derive
>   from a non-copyable class, i.e. one with the preceding issues--you will
> also
>   get 4511 and 4512.
>
Beman proposed changing noncopyable idiom to a macro.  This would solve not
only the
warning problems but also the problem of horrible compiler error messages
that results
from the current idiom.  I would welcome this change.  Then we could mark
the boost::noncopyable
class as deprecated

Zach