Re: [boost] [python] Tru64/CXX function template issues

From: Markus Schöpflin (markus.schoepflin_at_[hidden])
Date: 2005-06-20 02:41:16

David Abrahams wrote:

> Markus Schöpflin <markus.schoepflin_at_[hidden]> writes:

>>So I think as long as the bug in iotraits is not fixed, boost.python 
>>will not work on this platform, at least not with the boost.build 
>>toolset. :-(

> Note:  when using Boost.Build you are supposed to #include one of its
> headers first.  That means boost/python/detail/prefix.hpp gets
> #included before anything else, which gives you an opportunity to
> play all sorts of nasty tricks like
> 
>    #define ios_traits broken_ios_traits
>    #include <iotraits>
>    #undef ios_traits
> 
>    struct ios_traits  // the working version
>    {
> 
>    }
> 
> to work around brokenness.

The problem is, there is no working version of iotraits in this case. To 
summarize:

- The <iotraits> header file has broken support for std::fpos_t when it's 
not an integral value.

- The definition of std::fpos_t is normally taken from /usr/include/stdio.h.

- std::fpos_t as defined in stdio.h is not an integer value whenever 
_XOPEN_SOURCE >= 500. pyconfig.h forces the value to 600.

- When the compiler option pure_cname is in effect and /usr/include is not 
on the command line as include path, a different stdio.h is selected, which 
defines std::fpos_t as an itegral value, ignoring the setting of _XOPEN_SOURCE.

The last item is the explanation, why Ralf's setup works, because 
pure_cname is in effect by default whenever strict_ansi is in effect.

Now, the bb toolset cannot use pure_cname because test, fs, threads and 
maybe others need POSIX features. And I don't see how playing tricks in 
some boost.python header file could help here. Do you have an idea?

TIA, Markus