Expand description
ExternalPtr is a way to leak Rust allocated data to R, forego deallocation
to R and its GC strategy.
An ExternalPtr encompasses three values, an owned pointer to the Rust
type, a tag and a prot. Tag is a helpful naming of the type, but
it doesn’t offer any solid type-checking capability. And prot is meant
to be R values, that are supposed to be kept together with the ExternalPtr.
Neither tag nor prot are attributes, therefore to use ExternalPtr as
a class in R, you must decorate it with a class-attribute manually.
Beware: Equality (by way of PartialEq) does not imply equality of value,
but equality of pointer. Two objects stored as ExternalPtr may be equal
in value, but be two distinct entities, with distinct pointers.
Instead, rely on AsRef to make by value comparison, e.g. to compare
for equality of
two instances of ExternalPtr<T> by value, a.as_ref() == b.as_ref().
Structs§
- External
Ptr - Wrapper for creating R objects containing any Rust object.