Try switching match arms

autometrics-macros/src/lib.rs

@@ -106,14 +106,10 @@ fn instrument_function(args: &AutometricsArgs, item: ItemFn) -> Result<TokenStre
             }
         }
     } else {
-        let labels = quote! {
-            autometrics::result_labels!(&result)
-        };
-
         quote! {
             {
                 use autometrics::__private::{CALLER, CounterLabels, GetLabels};
-                let result_labels = #labels;
+                let result_labels = autometrics::result_labels!(&result);
                 CounterLabels::new(
                     #function_name,
                     module_path!(),

autometrics/src/labels.rs

@@ -250,27 +250,27 @@ macro_rules! result_labels {
                 }
             }
 
-            match<T: GetLabels, E> &Result<T, E> -> Option<ResultAndReturnTypeLabels> {
+            match<T, E: GetLabels> &Result<T, E> -> Option<ResultAndReturnTypeLabels> {
                 match val {
                     Ok(ok) => Some((
-                        ok.__autometrics_get_labels().unwrap_or(OK_KEY),
+                        OK_KEY,
                         ok.__autometrics_static_str(),
                     )),
                     Err(err) => Some((
-                        ERROR_KEY,
+                        err.__autometrics_get_labels().unwrap_or(ERROR_KEY),
                         err.__autometrics_static_str(),
                     )),
                 }
             }
 
-            match<T, E: GetLabels> &Result<T, E> -> Option<ResultAndReturnTypeLabels> {
+            match<T: GetLabels, E> &Result<T, E> -> Option<ResultAndReturnTypeLabels> {
                 match val {
                     Ok(ok) => Some((
-                        OK_KEY,
+                        ok.__autometrics_get_labels().unwrap_or(OK_KEY),
                         ok.__autometrics_static_str(),
                     )),
                     Err(err) => Some((
-                        err.__autometrics_get_labels().unwrap_or(ERROR_KEY),
+                        ERROR_KEY,
                         err.__autometrics_static_str(),
                     )),
                 }
@@ -290,11 +290,10 @@ macro_rules! result_labels {
             }
 
             match<T: GetLabels> &T -> Option<ResultAndReturnTypeLabels> {
-                val.__autometrics_get_labels().map(|label|
-                    (label, val.__autometrics_static_str()))
+                val.__autometrics_get_labels().map(|label| (label, val.__autometrics_static_str()))
             }
 
-            match<T> &T -> Option<ResultAndReturnTypeLabels> {
+            match<T> T -> Option<ResultAndReturnTypeLabels> {
                 None
             }
         }