nativePtr property
Internal: returns the native pointer for use by Session.
The pointee's type follows the backing — z_view_keyexpr_t or
z_owned_keyexpr_t — so this is only safe where the backing is known.
Use loanedKeyExpr, which is backing-aware, for everything else.
Implementation
Pointer<Void> get nativePtr {
_ensureAlive();
return _kePtr;
}