Re: Problems with header-only lib

From: David Abrahams (dave_at_[hidden])
Date: 2005-06-08 21:51:58

David Abrahams <dave_at_[hidden]> writes:

>> Does it work if you 
>> build with
>>
>> bjam asynch-exceptions=on
>>
>> ?
>
> Nope.

Okay, I fixed this part. The problem was a mistaken dependence on
the base-target-type feature, which I got from the prior state of
msvc.jam:

1.28 (vladimir 06-Jul-04): flags msvc.compile CFLAGS <base-target-type>CPP : /EHsc ;

I'm not sure how it ever worked, in fact. Can you explain how
<base-target-type>CPP would have ever been satisfied when trying to
produce an OBJ?

>> Also, note that most of the time usage requirements are free features. I'm not
>> sure that propagated features as usage requirements will quite as expected. 
>> For example
>>
>> rule copy.cpp /boost/test//minimal some_other_lib ;
>>
>> might propagate asynch-exceptions=on from minimal to 'copy.cpp', but I'm 
>> pretty sure it won't be propagated to some_other_lib -- because first all 
>> sources are built, and only then usage requirements for all sources are added
>> to build properties.
>
> Hmm, yes... well, I admit that I would not have expected it to be
> propagated to some_other_lib in that case, but it's also obvious to me
> that it needs to be propagated that way. So this looks like a serious
> architectural problem.

Of course, this part is still a problem, and really needs to be
properly resolved.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com