From: Hartmut Kaiser (hartmutkaiser_at_[hidden])
Date: 2004-01-03 17:21:57
Pavel Vozenilek wrote:
> > > > I am inclined towards a new policy for Boost which requires
> > > > compiler identification only via BOOST_-prefixed macros.
> > > >
> > > Not always:
> > >
> > > #if (defined _MSC_VER) && (_MSC_VER >= ...) # pragma once #endif
> > >
> > This may be done through a BOOST_HAS_PRAGMA_ONCE pp
> constant, because
> > are other preprocessors too, which support the #pragma once (for
> > instance Wave :-).
> Right but it would require to include configuration header
> before #pragma and this may negate any potential effect of the pragma.
> Also the Intel C++ may behave bug-by-bug or support GCC
> specific feature.
> I preferere BOOST_ macros, just not always.
It's a pain to re-iterate all the conditions and compilers, which support
the #pragma once for every
#if (defined(_MSC_VER) && _MSC_VER >= 1020) || defined(__WAVE__) || etc.
So I mandate for using a BOOST_... constant for this. The Boost.Config
headers are included first anyways, and not using a #pragma once inside
those shouldn't hurt so much.
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