Hash tables in elisp supports weak references, however weak references may be useful without the need to use a hash.
How can a weak reference to an object be defined without having to use a hash-table containing one item?
Hash tables in elisp supports weak references, however weak references may be useful without the need to use a hash.
How can a weak reference to an object be defined without having to use a hash-table containing one item?
General-purpose weak references would indeed be a useful general-purpose feature for elisp.
It's worth mentioning that in lieu of that functionality, there's a mini convenience library for exactly the strategy you mention (using a hash table with weak values and a single constant as a key) to obtain an effective weak reference: elisp-weak-ref.