RefType

Reference types classify first-class references to objects in the runtime store.

The type funcref denotes the infinite union of all references to functions, regardless of their function types.

The type externref denotes the infinite union of all references to objects owned by the embedder and that can be passed into WebAssembly under this type.

Reference types are opaque, meaning that neither their size nor their bit pattern can be observed. Values of reference type can be stored in tables.