Attribute Macro shared_fn

#[shared_fn]

shared_fn is used to define a function that will be exported by a plugin but is not directly callable by an Extism runtime. These functions can be used for runtime linking and mocking host functions for tests. If direct access to Wasm native parameters is needed, then a bare extern "C" fn should be used instead.

All arguments should implement extism_pdk::ToBytes and the return value should implement extism_pdk::FromBytes, if () or SharedFnResult<()> then no value will be returned.

Example

use extism_pdk::{SharedFnResult, shared_fn};
#[shared_fn]
pub fn greet2(greeting: String, name: String) -> SharedFnResult<String> {
  let s = format!("{greeting}, {name}");
  Ok(name)
}