catch errors on build_add explicitly

Author: mikeedjones

src/input/return_enums.rs

@@ -194,19 +194,22 @@ impl BuildSet for Bound<'_, PyFrozenSet> {
     }
 }
 
-fn validate_hashable<'py>(
+fn validate_add<'py>(
     py: Python<'py>,
-    item: &(impl Input<'py> + ?Sized),
+    set: &impl BuildSet,
+    item: impl BorrowInput<'py>,
     state: &mut ValidationState<'_, 'py>,
     validator: &CombinedValidator,
-) -> ValResult<PyObject> {
-    let result: PyObject = validator.validate(py, item, state)?;
-
-    let bound_result: &Bound<'_, PyAny> = result.bind(py);
-
-    match bound_result.hash() {
-        Ok(_) => Ok(result),
-        Err(_) => Err(ValError::new(ErrorTypeDefaults::SetItemNotHashable, item)),
+) -> ValResult<()> {
+    let validated_item = validator.validate(py, item.borrow_input(), state)?;
+    match set.build_add(validated_item) {
+        Ok(()) => Ok(()),
+        Err(err) => {
+            if err.matches(py, py.get_type::<PyTypeError>())? {
+                return Err(ValError::new(ErrorTypeDefaults::SetItemNotHashable, item));
+            }
+            Err(err)?
+        }
     }
 }
 
@@ -232,9 +235,8 @@ pub(crate) fn validate_iter_to_set<'py>(
             false => PartialMode::Off,
         };
         let item = item_result.map_err(|e| any_next_error!(py, e, input, index))?;
-        match validate_hashable(py, item.borrow_input(), state, validator) {
-            Ok(item) => {
-                set.build_add(item)?;
+        match validate_add(py, set, item, state, validator) {
+            Ok(()) => {
                 if let Some(max_length) = max_length {
                     if set.build_len() > max_length {
                         return Err(ValError::new(