Re: [Boost-users] [multi_index] function object as key extractor?

From: Joaquín Mª López Muñoz (joaquin_at_[hidden])
Date: 2007-03-16 09:25:27

Hello Andrew,

Andrew Holden ha escrito:

> Joaquín Mª López Muñoz wrote:
> >
> > Filip Konvi?ka ha escrito:
> > >
> > > Aye, I got the following warning that I could not get rid of (VC 7.1)
> > >
> > > C:\Boost\include\boost-1_33_1\boost\functional\hash\hash.hpp(132) :
> > > warning C4267: 'argument' : conversion from 'size_t' to 'unsigned int',
> > > possible loss of data
> >
> > [...]
> >
> > Looks like an overzealous or simply misguided warning. Can you please try
> > the following?
> >
> > [...]
> >
> > Same warning? If so, you might ask for inclusion of a suitable #pragma
> > warning(disable...) to the Boost.Hash author.
>
> Depending on your concern for portability, you might not want to dismiss this
> warning.  VC 7.1 and 8.0 provide it as part of their 64 bit portability warnings
> (size_t will be 64 bits wide on 64-bit Windows, while unsigned int will remain
> 32 bits).  A better way to eliminate the warning might be to switch off the
> 64 bit portability warnings in your project options.

I'm not advocating that the warning be completely disabled, but only in a
selective manner inside Boost.Hash code by using #pragma warning(push) and
#pragma warning(pop):

  // boost/hash/hash.hpp
  #pragma warning(push)
  #pragma warning(disable:4267)
  ...
  #pragma warning(pop)

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo