GuestErrorType only needs to have a success constructor

crates/wiggle/macro/src/lib.rs

@@ -66,16 +66,11 @@ use syn::parse_macro_input;
 ///
 /// /// For all types used in the `Error` position of a `Result` in the module
 /// /// traits, you must implement `GuestErrorType` which tells wiggle-generated
-/// /// code how to determine if a method call has been successful, as well as
-/// /// how to translate a wiggle runtime error into an ABI-level error.
-/// impl<'a> GuestErrorType<'a> for types::Errno {
-///     type Context = YourCtxType;
+/// /// code what value to return when the method returns Ok(...).
+/// impl GuestErrorType for types::Errno {
 ///     fn success() -> Self {
 ///         unimplemented!()
 ///     }
-///     fn from_error(_e: wiggle::GuestError, _c: &Self::Context) -> Self {
-///         unimplemented!()
-///     }
 /// }
 ///
 /// # fn main() { println!("this fools doc tests into compiling the above outside a function body")