Attribute Macro externref 

#[externref]

Available on crate feature macro only.

Prepares imported functions or an exported function with Resource args and/or return type.

Inputs

This attribute must be placed on an extern "C" { ... } block or an extern "C" fn. If placed on block, all enclosed functions with Resource args / return type will be wrapped.

Processing

The following arg / return types are recognized as resources:

• Resource<_>, &Resource<_>, &mut Resource<_>
• Option<_> of any of the above three variations