[boost] Re: How are boost/mpl/aux_/preprocessed files generated?

From: Larry Evans (cppljevans_at_[hidden])
Date: 2005-06-10 17:59:25

On 06/10/2005 05:09 PM, Jonathan Turkanis wrote:
> Larry Evans wrote:
[snip]
> The point of preprocessing certain headers is just to save the compiler from
> having to preprocess them on each compilation. The main work is done by the
> preprocessor itself.
More specifically, by the preprocess.py's:

       os.system( "preprocess %s %s %s %s" % ( boost_root, mode, file,
       file_path ) )

IIUC.

But then why isn't the result of this  preprocessing and then clean-up
by the python code placed in:

   boost/mpl/<basename>.hpp

instead of in:

   boost/mpl/aux_/preprocessed/<mode>/<basename>.hpp

where <basename> is some basename of the files in boost/mpl/*.hpp and 
<mode> is some directory in boost/mpl/aux_/preprocessed and also,
apparently, one possible value of mode in:

   def process( file, boost_root, dst_dir, mode ):

in libs/mpl/preprocessed/preprocess.py?  The way it's done now,
by using some preprocessing flags in:

  boost/mpl/<basename>.hpp

to indicate whether:

  boost/mpl/aux_/preprocessed/<mode>/<basename>.hpp

is to be included or not, makes it harder to understand what's
going on.