Address review feedback

- Don't wrap the non_root_python_to_rust exception in value_set
- Allow subclasses of the declared value type (isinstance check)
- Document why value set decoding uses a linear member scan

https://claude.ai/code/session_01AbKLBGrHu13j6gKNpKGD2e

Author: claude

src/cryptography/hazmat/asn1/asn1.py

@@ -440,12 +440,7 @@ def value_set(
     their value; decoding fails if the decoded value does not match
     any member.
     """
-    try:
-        rust_type = declarative_asn1.non_root_python_to_rust(value_type)
-    except TypeError:
-        raise TypeError(
-            f"unsupported value type for value set: {value_type!r}"
-        )
+    rust_type = declarative_asn1.non_root_python_to_rust(value_type)
 
     def decorator(cls: type[U]) -> type[U]:
         if not issubclass(cls, enum.Enum):
@@ -458,7 +453,7 @@ def decorator(cls: type[U]) -> type[U]:
                 f"value set '{cls.__name__}' must have at least one member"
             )
         for member in members:
-            if type(member.value) is not value_type:
+            if not isinstance(member.value, value_type):
                 raise TypeError(
                     f"member '{member.name}' of value set '{cls.__name__}' "
                     f"must have a value of type "

src/rust/src/declarative_asn1/decode.rs

@@ -266,6 +266,11 @@ fn decode_value_set<'a>(
 ) -> ParseResult<pyo3::Bound<'a, pyo3::PyAny>> {
     let inner_ann_type = value_set_inner_type(py, inner_type, annotation)?;
     let decoded = decode_annotated_type(py, parser, &inner_ann_type)?;
+    // NOTE: This is a linear scan over the members of the enum. If this
+    // ever becomes a performance problem, it could be replaced with a
+    // value -> member map stored in `Type::ValueSet` (keeping in mind
+    // that hash-based lookups won't work for the asn1 wrapper types,
+    // which implement `__eq__` but not `__hash__`).
     for member in cls.bind(py).try_iter()? {
         let member = member?;
         if member.getattr(pyo3::intern!(py, "value"))?.eq(&decoded)? {

tests/hazmat/asn1/test_api.py

@@ -572,6 +572,6 @@ class Example(enum.Enum):
     def test_fail_unsupported_value_type(self) -> None:
         with pytest.raises(
             TypeError,
-            match="unsupported value type for value set",
+            match="cannot handle type",
         ):
             asn1.value_set(float)