Py.CapsuleSourceEmbedding of OCaml values in Python.
For a given type 'a, create s returns a pair { wrap; unwrap }. wrap v transforms the value v of type 'a to an opaque Python object. unwrap w transforms the opaque Python object w previously obtained with wrap v into the original OCaml value v, such that unwrap (wrap v) = v. Failure _ is raised if a wrapper has already been generated for a type of the same name.
Same as create, but returns a plain pair instead of a record.
type_of w returns the type string associated to the opaque Python object w.
Wrapper for PyCapsule_IsValid. OCaml capsules have the name "ocaml-capsule". We have check v = is_valid v "ocaml-capsule".
unsafe_wrap_value v transforms the value v to an opaque Python object.