[boost] Re: boost::optional - Include none.hpp instead of none_t.hpp?

From: Fernando Cacciola (fernando_cacciola_at_[hidden])
Date: 2004-06-02 11:08:14

<Schalk_Cronje_at_[hidden]> escribió en el mensaje
news:2E22904642859A40AF5E1CA1597EBB1F12FF25_at_devexmb1.corp.nai.org...
> Was it intentional to include none_t.hpp instead of none.hpp in
boost/optional.hpp?
> Otherwise it seems that the user must resort to including
boost/detail/none.hpp
>
Well, yes, it was.
The reason is that the Borland compiler (at least BCB6) refuses to create a
precompiled header with data on it, not even pointer constants. Therefore,
none.hpp cannot be in a precompiled header (PCH); and any header including
it won't be allowed in a PCH.
As I see optional<> as ubiquitous, I decoupled none.hpp from it so that
Optional users (specially for BCB) can put it in a PCH. The drawback is that
users wanting to use "none" must include it separately.
Now, OTOH, I think "none.hpp" should leave in the root directory and not on
detail. I initially put it there but some people argued that it was Optional
specific, but since there is no /optional subdir I moved it into /detail

Fernando Cacciola
SciSoft