NullablePointer[A: A]¶
A NullablePointer[A] is used to encode a possibly-null type. It should only be used for structs that need to be passed to and from the C FFI.
An optional type for anything that isn't a struct should be encoded as a union type, for example (A | None).
struct ref NullablePointer[A: A]
Constructors¶
create¶
This re-encodes the type of that from A to NullablePointer[A], allowing
that to be assigned to a field or variable of type NullablePointer[A]. It
doesn't allocate a wrapper object: there is no containing object for that.
new ref create(
that: A)
: NullablePointer[A] ref^
Parameters¶
- that: A
Returns¶
- NullablePointer[A] ref^
none¶
This returns a null pointer typed as a NullablePointer[A].
new ref none()
: NullablePointer[A] ref^
Returns¶
- NullablePointer[A] ref^
Public Functions¶
apply¶
This re-encodes the type of this from NullablePointer[A] to A, allowing
this to be assigned to a field of variable of type A. If this is a null
pointer, an error is raised.
fun box apply()
: this->A ?
Returns¶
- this->A ?
is_none¶
Returns true if this is null (ie apply would raise an error).
fun box is_none()
: Bool val
Returns¶
- Bool val