Not included as part of the subset linked above, but D's Contract Programming piqued my interest: https://dlang.org/spec/contracts.html
Contract-based programming is a very nice way to quickly find errors and specify how different parts of the program should interact.
There are some Java annotation processors that rewrite the bytecode for contracts.
As extra info.
It's another layer of complexity, but it extends the language to offer a bit more richness or layers of abstraction.
I would not be surprised if a future C++ standard adds contracts officially. Boost seems to already have contracts: https://www.boost.org/doc/libs/1_67_0/libs/contract/doc/html...
On the .NET side you have Roslyn, Attributes, expression trees and on F# quotations.
While they are all a bit cumbersome to use versus what Lisp macros allow for, they already allow for quite a lot.
Yes, there is some hope that C++23 will bring them.
The more languages support DbC the better, only so can we start seeing more widespread adoption across the industry.