Function from_user_data 

pub unsafe fn from_user_data(
    mrb: *mut mrb_state,
) -> Result<Artichoke, InterpreterExtractError>

Extract an Artichoke interpreter from the user data pointer on a sys::mrb_state.

Calling this function will move the State out of the sys::mrb_state into the Artichoke interpreter.

Safety

This function assumes that the user data pointer was created with Box::into_raw and that the pointer is to a non-free’d Box<State>.