pub(crate) fn external_arg(ty: &Type) -> Option<ExternalArg>Expand description
The borrowed external argument ty describes, if any: &T / &mut T
where T names a type with no R-side conversion of its own (no type
check, not in NOT_EXTERNAL), or an ExternalPtrRef<'_, T> /
ExternalPtrMut<'_, T> view, either one optionally under Option.
Matched on the written type: a &T whose T isn’t TypedExternal is a
compile error at the type (ExternalPtr<T> requires it).