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

From: Jonathan Turkanis (technews_at_[hidden])
Date: 2005-06-10 18:09:36

Larry Evans wrote:
> 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

That would overwrite the source code, which would make it impossible for users
to turn off preprocessing or to use the source with the full range of supported
compilers.

Jonathan