specialize count for PageRange and PhysFrameRange

Author: Freax13

src/structures/paging/frame.rs

@@ -165,6 +165,15 @@ impl<S: PageSize> Iterator for PhysFrameRange<S> {
             None
         }
     }
+
+    #[inline]
+    fn count(self) -> usize {
+        if !self.is_empty() {
+            ((self.end.start_address() - self.start.start_address()) / S::SIZE) as usize
+        } else {
+            0
+        }
+    }
 }
 
 impl<S: PageSize> fmt::Debug for PhysFrameRange<S> {

src/structures/paging/page.rs

@@ -305,6 +305,15 @@ impl<S: PageSize> Iterator for PageRange<S> {
             None
         }
     }
+
+    #[inline]
+    fn count(self) -> usize {
+        if !self.is_empty() {
+            ((self.end.start_address() - self.start.start_address()) / S::SIZE) as usize
+        } else {
+            0
+        }
+    }
 }
 
 impl PageRange<Size2MiB> {