Add default __richcmp__ for enums.

Author: jovenlin0527

pyo3-macros-backend/src/pyclass.rs

@@ -386,7 +386,6 @@ struct PyClassEnum<'a> {
     // The underyling representation of the enum.
     // It's used to implement __int__ and __richcmp__.
     // This matters when the underyling representation may not fit in `isize`.
-    #[allow(unused, dead_code)]
     repr: syn::Ident,
     variants: Vec<PyClassEnumVariant<'a>>,
     doc: PythonDoc,
@@ -502,7 +501,30 @@ fn impl_enum_class(
         }
     };
 
-    let default_impls = gen_default_slot_impls(cls, vec![default_repr_impl]);
+    let default_richcmp = {
+        let variants_eq = variants.iter().map(|variant| {
+            let variant_name = variant.ident;
+            quote! {(#cls::#variant_name, #cls::#variant_name) => true.to_object(py),}
+        });
+        quote! {
+            #[doc(hidden)]
+            #[allow(non_snake_case)]
+            #[pyo3(name = "__richcmp__")]
+            fn __pyo3__richcmp__(&self, py: ::pyo3::Python, other: &Self, op: ::pyo3::basic::CompareOp) -> PyObject {
+                match op {
+                    ::pyo3::basic::CompareOp::Eq => {
+                        match (self, other) {
+                            #(#variants_eq)*
+                            _ => false.to_object(py),
+                        }
+                    }
+                    _ => py.NotImplemented(),
+                }
+            }
+        }
+    };
+
+    let default_impls = gen_default_slot_impls(cls, vec![default_repr_impl, default_richcmp]);
     Ok(quote! {
 
         #pytypeinfo

tests/test_enum.rs

@@ -12,12 +12,11 @@ pub enum MyEnum {
 
 #[test]
 fn test_enum_class_attr() {
-    let gil = Python::acquire_gil();
-    let py = gil.python();
-    let my_enum = py.get_type::<MyEnum>();
-    py_assert!(py, my_enum, "getattr(my_enum, 'Variant', None) is not None");
-    py_assert!(py, my_enum, "getattr(my_enum, 'foobar', None) is None");
-    py_run!(py, my_enum, "my_enum.Variant = None");
+    Python::with_gil(|py| {
+        let my_enum = py.get_type::<MyEnum>();
+        let var = Py::new(py, MyEnum::Variant).unwrap();
+        py_assert!(py, my_enum var, "my_enum.Variant == var");
+    })
 }
 
 #[pyfunction]
@@ -26,7 +25,6 @@ fn return_enum() -> MyEnum {
 }
 
 #[test]
-#[ignore] // need to implement __eq__
 fn test_return_enum() {
     let gil = Python::acquire_gil();
     let py = gil.python();
@@ -42,14 +40,24 @@ fn enum_arg(e: MyEnum) {
 }
 
 #[test]
-#[ignore] // need to implement __eq__
 fn test_enum_arg() {
-    let gil = Python::acquire_gil();
-    let py = gil.python();
-    let f = wrap_pyfunction!(enum_arg)(py).unwrap();
-    let mynum = py.get_type::<MyEnum>();
+    Python::with_gil(|py| {
+        let f = wrap_pyfunction!(enum_arg)(py).unwrap();
+        let mynum = py.get_type::<MyEnum>();
 
-    py_run!(py, f mynum, "f(mynum.Variant)")
+        py_run!(py, f mynum, "f(mynum.OtherVariant)")
+    })
+}
+
+#[test]
+fn test_enum_eq() {
+    Python::with_gil(|py| {
+        let var1 = Py::new(py, MyEnum::Variant).unwrap();
+        let var2 = Py::new(py, MyEnum::Variant).unwrap();
+        let other_var = Py::new(py, MyEnum::OtherVariant).unwrap();
+        py_assert!(py, var1 var2, "var1 == var2");
+        py_assert!(py, var1 other_var, "var1 != other_var");
+    })
 }
 
 #[test]