Re: Modules

From: Zach Laine (whatwasthataddress_at_[hidden])
Date: 2020-08-22 22:40:06

On Fri, Aug 21, 2020 at 1:54 PM Damian Vicino via Boost
<boost_at_[hidden]> wrote:
>
> Hi,
> Are there any guidelines on the use of modules inside boost?
> Are we planning any steps for adoption of them?

Modules are pretty hard for most Boost libs to adopt.  Consider how
many times we have code like this:

#if BOOST_LIBNAME_DO_WHATEVER
some_code;
#else
come_other_code;
#endif

That cannot exist inside a module.  The net result is that your code
has to be all the same lexically -- for all compilers and platforms --
if it is in a module.  Such macro-conditional code can be written in
headers that are #included at the top of a module, but that module
must always be built with the same definition of
BOOST_LIBNAME_DO_WHATEVER.

Of course, we have no support for modules in Boost build either, which
is what you were asking I think.  I think the motivation for all the
work that would require is somewhat low.

Zach