Re: Changes in buildable components over time

From: Glen Fernandes (glen.fernandes_at_[hidden])
Date: 2022-04-15 19:29:02

On Thu, Apr 7, 2022 at 11:12 AM Tim Haines via Boost
<boost_at_[hidden]> wrote:
> Surprisingly, though, it appears that coroutine2 and metaparse started out
> as buildable components, but then switched to being header-only.
>
> coroutine2
>  - introduced in 1.59.0
>  - first buildable in 1.59.0
>  - last buildable in 1.64.0
>  - available as of 1.78.0
>
> metaparse
>  - introduced in 1.61.0
>  - first buildable in 1.61.0
>  - last buildable in 1.65.1
>  - available as of 1.78.0
>
> I cross-referenced the release notes, but I didn't see any mention of these
> components being made header-only. Is this intended behavior?

Metaparse was always header-only, but prior to 1.66.0 it had a
build/Jamfile.v2 which just built examples and tests:
    build-project ../example ;
    build-project ../test ;

This isn't best-practices, and so build/Jamfile.v2 was rightly removed.

Coroutine2 did become header-only in 2017:
https://github.com/boostorg/coroutine2/commit/5b06384117d19b8ce8b52678fe7f62d9f1354155

This wasn't mentioned in the release notes.

We can probably do a better job of indicating which libraries are
header-only and which are not. Maybe the
https://www.boost.org/doc/libs/1_79_0/ list is the best place.

(The list on https://www.boost.org/doc/libs/1_79_0/more/getting_started/windows.html
is out of date too.)

Glen