Re: [Boost-users] Serialization - 'size_t' to'std::streamsize' error

From: Dave Nay (dave.nay_at_[hidden])
Date: 2007-11-19 16:11:11

Thanks Mike,

I understood the reason for the error (signed vs. unsigned).  I was (am)
just confused as to why this error is showing up within the Boost
serialization code (not my code, Boost code).  I have added explicit casts
to the locations in the basic_binary_oprimitive.hpp and
basic_binary_iprimitive.hpp header files, and this of course supresses the
errors, but it doesn't really satisfy my confusion.

Dave

-----Original Message-----
From: boost-users-bounces_at_[hidden]
[mailto:boost-users-bounces_at_[hidden]] On Behalf Of Michael Linck
Sent: Friday, November 09, 2007 5:41 PM
To: boost-users_at_[hidden]
Subject: Re: [Boost-users] Serialization - 'size_t' to'std::streamsize'
error

I'm surprised this didn't seem to get answered.  I wouldn't worry about the
warning in your case.  Here's the difference: size_t is unsigned, streamsize
is signed.  This means that if they're both the same datawidth - which is
likely - you'll get the warning below because the range of size_t tops out
at a *much* higher value than that of streamsize.

If you're really concerned about this you may be able to use boost numerics
to validate that the value of size_t is actually within the range of
streamsize.  To merely quell the warning, an explicit cast should do the
trick.

mike

On Wed, 2007-10-31 at 11:57 -0500, Dave Nay wrote:
> Ok....this is really confusing.
> 
> I successfully created a small test project several months ago using 
> the Boost Serialization library to serialize some binary data.  I am 
> now attempting to add binary serialization to a production project, 
> and I receive a bunch of compiler warnings.
> 
> I can still compile and execute the test application with no warnings 
> or errors.
> 
> I am using VS2005 with boost 1.34.1
> 
> I have included the first few compiler warnings below...
> 
> 1>C:\Program
> Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(136) :
> warning C4267: 'argument' : conversion from 'size_t' to 
> 'std::streamsize', possible loss of data
> 1>        C:\Program
> Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(120) :
> while compiling class template member function 'void 
> boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save_binary(
> const
> void *,size_t)'
> 1>        with
> 1>        [
> 1>            Archive=boost::archive::binary_oarchive,
> 1>            Elem=char,
> 1>            Tr=std::char_traits<char>
> 1>        ]
> 1>        C:\Program
> Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(91) : 
> see reference to function template instantiation 'void 
> boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save<T>(cons
> t T &)' being compiled
> 1>        with
> 1>        [
> 1>            Archive=boost::archive::binary_oarchive,
> 1>            Elem=char,
> 1>            Tr=std::char_traits<char>,
> 1>            T=unsigned char
> 1>        ]
> 1>        C:\Program
> Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(244) : 
> see reference to function template instantiation 'void 
> boost::archive::save_access::save_primitive<Archive,T>(Archive &,const T
&)'
> being compiled
> 1>        with
> 1>        [
> 1>            Archive=boost::archive::binary_oarchive,
> 1>            T=unsigned char
> 1>        ]
> 
> Thanks,
> Dave
> 
> --
> Dave Nay
> CIVision, LLC
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users

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