pub fn derive_external_ptr(input: DeriveInput) -> Result<TokenStream>Expand description
Main entry point for #[derive(ExternalPtr)].
Orchestrates the full derive expansion:
- Parses
#[externalptr(...)]attributes for class system selection. - Analyzes struct fields for
#[r_data]sidecar slots. - Generates
TypedExternalimpl (type identity forExternalPtr<T>). - Generates
IntoExternalPtrmarker impl (enablesIntoRblanket impl). - Generates sidecar accessor FFI functions, registration constants, and R wrappers.
Returns the combined token stream of all generated items.