Add support for modular build structure.

[grafikrobot]

This is part of the effort to make the Boost libraries "modular" for build and consumption. See https://lists.boost.org/Archives/boost/2024/01/255704.php and https://github.com/grafikrobot/boost-b2-modular/blob/b2-modular/README.adoc for more information.

This PR depends on the following other PRs being merged to both develop and master branches of the respective repos:

• Add support for modular build structure. boost#854

[vinniefalco]

Can I merge this or do we have to wait?

[grafikrobot]

We have to wait until the PR referenced is merged. I'll change this from Draft to Ready when you can merge.

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[grisumbras]

This PR adds build.jam, and leaves Jamfile unchanged. Can I remove Jamfile and put its contents into build.jam instead?

[grafikrobot]

This PR adds build.jam, and leaves Jamfile unchanged. Can I remove Jamfile and put its contents into build.jam instead?

Hm.. Looks like I missed that there was a Jamfile. I'll incorporate the equivalent into the build.jam.

[grafikrobot]

@grisumbras okay, I added the test project to the all target. So, yes, you can delete the Jamfile once the build.jam is in.

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html

[grafikrobot]

@grisumbras okay, I added the test project to the all target. So, yes, you can delete the Jamfile once the build.jam is in.

NM.. I deleted it as part of this PR. Should be good to merge, again.

[cppalliance-bot]

An automated preview of the documentation is available at https://143.docca.prtest.cppalliance.org/tools/docca/example/html/index.html