Re: [boost] [Boost-bugs] [ boost-Bugs-1567815 ] Excessive warnings onMSVC

From: Paul A Bristow (pbristow_at_[hidden])
Date: 2006-09-29 13:01:24

|  -----Original Message-----
|  From: boost-bounces_at_[hidden] 
|  [mailto:boost-bounces_at_[hidden]] On Behalf Of SourceForge.net
|  Sent: 29 September 2006 16:22
|  To: noreply_at_[hidden]
|  Subject: [boost] [Boost-bugs] [ boost-Bugs-1567815 ] 
|  Excessive warnings onMSVC
|  
|  Bugs item #1567815, was opened at 2006-09-29 11:21
|  Message generated for change (Tracker Item Submitted) made 
|  by Item Submitter
|  You can respond by visiting: 
|  https://sourceforge.net/tracker/?func=detail&atid=107586&aid=
|  1567815&group_id=7586
|  
|  Please note that this message will contain a full copy of 
|  the comment thread,
|  including the initial issue submission, for this request,
|  not just the latest update.
|  Category: function
|  Group: None
|  Status: Open
|  Resolution: None
|  Priority: 5
|  Submitted By: Douglas Gregor (dgregor)
|  Assigned to: Douglas Gregor (dgregor)
|  Summary: Excessive warnings on MSVC
|  
|  Initial Comment:
|  I'm getting a large number of C4127, "conditional expression 
|  is constant", 
|  warnings from function_template.hpp:141. Can we do something about 
|  these?

We can and should  - and I am setting a good example adding them to John
Maddock's

<plug>
 upcoming for preview "Math functions and Statistical Distributions".
<\plug>

So they should all compile cleanly with the 'strictest' compiler options.

At very least, putting near the start but AFTER other #include <boost/....>

#ifdef BOOST_MSVC
#  pragma warning(push)
#  pragma warning(disable: 4127) // conditional expression is constant.
... and, if appropriate, others like
#  pragma warning(disable: 4189) // local variable is initialized but not
referenced.
#endif

and at the end

#ifdef BOOST_MSVC
# pragma warning(pop)
#endif

#endif //BOOST_???_HPP

But I note that using the normally recommended

#ifdef BOOST_MSVC

can fail to have the desired effect unless it is preceeded by an (probably
implicit) include of Boost config that will set the macro from _MSC_VER.
This is not normally a problem with Boost headers.

Paul

---
Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
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