Re: [boost] [system] Why is this not header-only?

From: Andrey Semashev (andysem_at_[hidden])
Date: 2007-04-02 13:11:56

Hello Jeff,

> Alexander Nasonov wrote:

>> IIRC, someone asked recently why asio requires -lboost_system at link time.
>> 
>> In my personal opinion, C++ wrappers for OS services should not be header-only. 
>> I would prefer asio, process, shmem and the like to be all consistent with 
>> boost.filesystem. Opinions?

> I think they should, if practical, have an option to be used as header only.
>    Implementations should be put in .ipp files and controlled by a macro like:

>    BOOST_ALLOW_ALL_HEADER_WITH_SYSTEM_INCLUDES

> If you don't add this macro then you have to link the library -- otherwise
> it's header only. I realize it's a bit more work for the library developers,
> but that way we can have it both ways.  I see this as like having an 'all
> inclusive' header for a library even though there are more granular headers --
> it makes it easy to get started and it actually handles the majority  of the
> cases where people don't care about optimizing 'include performance'.

Although the discussion is slipping away from the original question, I
must say I 100% agree with Jeff. The best solution is to give user a
choice whether to link or to go header-only (where possible). And in
my opinion such solution should be unified for all boost libs.
We already have the BOOST_USE_WINDOWS_H macro, why not extend it to
something like BOOST_USE_OS_NATIVE_HEADERS? I think this would settle
the problem once and for all. The only problem is I'm not sure how
such a transition should be organized.

-- 
Best regards,
 Andrey                            mailto:andysem_at_[hidden]