Added size_hint impls for {PyDict,PyList,PySet,PyTuple}Iterators

PyO3 · Jun 27, 2021 · d796aa6 · d796aa6
1 parent 190eb72
commit d796aa6
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Showing 4 changed files with 23 additions and 0 deletions.
diff --git a/src/types/dict.rs b/src/types/dict.rs
@@ -203,6 +203,12 @@ impl<'py> Iterator for PyDictIterator<'py> {
             }
         }
     }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.dict.len().unwrap_or_default();
+        (len, Some(len))
+    }
 }
 
 impl<'a> std::iter::IntoIterator for &'a PyDict {

diff --git a/src/types/list.rs b/src/types/list.rs
@@ -151,6 +151,12 @@ impl<'a> Iterator for PyListIterator<'a> {
             None
         }
     }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.list.len();
+        (len, Some(len))
+    }
 }
 
 impl<'a> std::iter::IntoIterator for &'a PyList {

diff --git a/src/types/set.rs b/src/types/set.rs
@@ -172,6 +172,12 @@ impl<'py> Iterator for PySetIterator<'py> {
             }
         }
     }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.set.len().unwrap_or_default();
+        (len, Some(len))
+    }
 }
 
 impl<'a> std::iter::IntoIterator for &'a PySet {

diff --git a/src/types/tuple.rs b/src/types/tuple.rs
@@ -121,6 +121,11 @@ impl<'a> Iterator for PyTupleIterator<'a> {
             None
         }
     }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.length, Some(self.length))
+    }
 }
 
 impl<'a> IntoIterator for &'a PyTuple {