Draft a paper on why C++ needs a type erasing wrapper

A self-contained document on motivation for type-erasing wrappers would be useful to frame discussion for protocol and for proxy. We should look into collaboration with @mingxwa to produce this design-independent paper.

The C++ committee forbids the use of AI in producing papers so this must be human written. Presumably we can use AI to help with proofreading.

Start by reviewing the issue's motivation for type-erasing wrappers in the context of protocol and proxy, then coordinate with @mingxwa on the intended scope. Done means producing a self-contained, design-independent, human-written paper that frames the discussion for both areas.

Written by the indexing model from the issue text.