Fix class method

Author: joohongpark

Lib/test/test_float.py

@@ -1525,8 +1525,6 @@ def roundtrip(x):
             else:
                 self.identical(x, fromHex(toHex(x)))
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_subclass(self):
         class F(float):
             def __new__(cls, value):

vm/src/builtins/float.rs

@@ -13,7 +13,7 @@ use crate::{
         PyComparisonValue,
     },
     protocol::{PyNumber, PyNumberMethods},
-    types::{AsNumber, Comparable, Constructor, Hashable, PyComparisonOp},
+    types::{AsNumber, Callable, Comparable, Constructor, Hashable, PyComparisonOp},
     AsObject, Context, Py, PyObject, PyObjectRef, PyPayload, PyRef, PyResult,
     TryFromBorrowedObject, TryFromObject, VirtualMachine,
 };
@@ -481,11 +481,13 @@ impl PyFloat {
         Ok((numer, denom))
     }
 
-    #[pymethod]
-    fn fromhex(repr: PyStrRef, vm: &VirtualMachine) -> PyResult<f64> {
-        float_ops::from_hex(repr.as_str().trim()).ok_or_else(|| {
-            vm.new_value_error("invalid hexadecimal floating-point string".to_owned())
-        })
+    #[pyclassmethod]
+    fn fromhex(cls: PyTypeRef, string: PyStrRef, vm: &VirtualMachine) -> PyResult {
+        let result = float_ops::from_hex(string.as_str().trim());
+        match result {
+            Some(value) => PyType::call(&cls, vec![vm.ctx.new_float(value).into()].into(), vm),
+            None => Err(vm.new_value_error("invalid hexadecimal floating-point string".to_owned())),
+        }
     }
 
     #[pymethod]