Re: cool generators insight

From: David Abrahams (gclbb-jamboost_at_[hidden])
Date: 2003-06-05 08:56:14

Vladimir Prus <ghost_at_[hidden]> writes:

>> Vladimir Prus <ghost_at_[hidden]> writes:
>> > {CPP,CPP} <- ECPP (only first CPP must be further converted into NM_ASM)
>>
>> How is that not an automatic ambiguity?
>
> I don't know what's "automatic ambiguity". I don't see anything wrong about 
> processing the first file in a different way from the second.

They're the same type. How can you expect the generator process to
deduce that the first one should be converted to NM_ASM and the
second one should not, instead of doing it the other way? You've
given no information to indicate which file to choose for that transformation.

>> You might get around that by generating a derived type of CPP,
>> e.g. NM_CPP, which can be converted into NM_ASM.
>
> Say, I write
>
> nm_exe foo : foo.cpp ;
>
> Here's "foo.cpp" is of type CPP, and it should be converted into NM_ASM. 
> Writing 
> 
> nm_exe foo : foo.nm_cpp
>
> is not that nice.

It seems to me that your case is one which cannot be automatically
solved without ambiguity.

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