Boost logo

Boost :

Subject: Re: [boost] [type_traits] Rewrite and dependency free version
From: John Maddock (jz.maddock_at_[hidden])
Date: 2015-02-01 05:45:55

>> 2) What do we do about common_type?
> This is still not addressed, right?
> Can you say what the current state of the rewrite is, the intention of how
> it will be used (ie, replace existing vs maintained in parallel), and
> blockers to reaching that point?

I've been suffering from sudden laptop failure, which is why I've been
silent on this - I'll post more when I'm up and running again - but the
current version of the branch should have a common_factor which only has
dependencies outside of Boost.Config for broken/obsolete compilers
(please note: I haven't fully tested/checked this, and won't until my
new laptop arrives sometime next week). In such a case I think it would
be acceptable to manually mark up that header with some "don't track
dependencies" directive and require users to manually add Boost.Typeof
to their list of required modules if they're using an old compiler.

Note that we need some kind of markup facility to deal with optional
dependencies anyway - to avoid the "everything depends on Serialization"
issue. So maybe something like:


BPM nodepend
BPM start_message
Note: If you're using boost::common_type with a compiler that supports
neither the decltype nor typeof keywords, then you will need to manually
add the "typeof" library to your download list.
BPM end_message


Other than that, I've nearly finished testing the new version and IMO it
looks good enough to simply replace the old version - but again more later.


Boost list run by bdawes at, gregod at, cpdaniel at, john at