From a21c6fb8ee810133ed8b00a46835a9c82915b703 Mon Sep 17 00:00:00 2001
From: TheAnyKey <ich@simonroth.de>
Date: Sun, 31 May 2020 21:43:42 +0000
Subject: [PATCH] implementation of Py310 int.bit_count

---
 vm/src/obj/objint.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/vm/src/obj/objint.rs b/vm/src/obj/objint.rs
index 7db7d69d1..615e8a2f6 100644
--- a/vm/src/obj/objint.rs
+++ b/vm/src/obj/objint.rs
@@ -653,6 +653,18 @@ impl PyInt {
     fn denominator(&self) -> usize {
         1
     }
+
+    #[pymethod]
+    /// Returns the number of ones 1 an int. When the number is < 0,
+    /// then it returns the number of ones of the absolute value.
+    fn bit_count(&self) -> u32 {
+        self.value
+            .to_u32_digits()
+            .1
+            .iter()
+            .map(|n| n.count_ones())
+            .sum()
+    }
 }
 
 #[derive(FromArgs)]