Re: On splitting headers

From: vesa_karvonen (vesa_karvonen_at_[hidden])
Date: 2002-02-06 10:11:05

--- In boost_at_y..., "Brey, Edward D" <EdwardDBrey_at_e...> wrote:
>Suppose I'm coding along in my project and I find I need a
>scoped_ptr. I include <boost/smart_ptr.hpp> in my precompiled
>header. I pay for a recompile of everything.  It's worth it, of
>course, because subsequent incremental compilations are much
>faster. Now suppose I need scoped_array. Well, as luck would have
>it, I don't have to recompile everything. Had I been using maximally
>small granularity, I would have had to put <boost/scoped_array.hpp>
>into my precompile header and paid for a full recompile. Instead, by
>paying for a trivially longer precompilation, which included some
>classes I didn't immediately use, I saved myself time in the long
>run.

I think that your logic is flawed.

Here is how the scenario would go when using minimal headers:

When you find that you need scoped_ptr in some translation unit, you 
include it there and recompile only the translation unit.

When you later find that you need scoped_array in some translation 
unit, you include it there and recompile only the translation unit.

In a very large project, you would have been able to compile and test 
both changes in a couple of minutes using minimal granularity 
headers. With precompiled headers it might have taken all day to 
recompile the whole project.