deprecated: MPL, foreach, typeof, ratio, chrono, assign, more?

From: Vinnie Falco (vinnie.falco_at_[hidden])
Date: 2024-10-04 18:21:34

Should one or more of these libraries be marked as "deprecated" in their
corresponding meta/libraries.json?

Array
Assign
Chrono
Compatibility
compressed_pair
enable_if
ForEach
functional
mem_fn
move
MPL
Ratio
ResultOf
Typeof

The new website could use this information to annotate the library. We
could add a "reason" field to libraries.json which is displayed on the
site. The website could have a checkbox, "hide deprecated", enabled by
default. We could show the reason for the deprecation. For example, that
mp11 is a more modern and functional version of MPL. Or that ForEach is now
a C++ language feature.

The authors and maintainers of those libraries would need to opt-in to
this, although we could have someone work up pull requests for some or all
of those libraries. There might be more libraries that belong on the list,
feel free to add.

Another idea we might consider is to add a preprocessor deprecation
warning, unless the user opts-in by defining BOOST_ALLOW_DEPRECATED or
something. Before we do that though, we should ensure that no
non-deprecated Boost libraries are using the above libraries.

Thanks