fix(variadics): fix HomogenousVariadic get and get_mut only ret…

…urning `None` (#1325)

variadics/src/lib.rs

@@ -330,15 +330,15 @@ where
         if i == 0 {
             Some(item)
         } else {
-            rest.get(i)
+            rest.get(i - 1)
         }
     }
     fn get_mut(&mut self, i: usize) -> Option<&mut T> {
         let (item, rest) = self;
         if i == 0 {
             Some(item)
         } else {
-            rest.get_mut(i)
+            rest.get_mut(i - 1)
         }
     }
 
@@ -470,4 +470,13 @@ mod test {
         );
         assert!(ref_iter.next().is_none());
     }
+
+    #[test]
+    fn test_homogenous_get() {
+        let mut var = var_expr!(0, 1, 2, 3, 4);
+        for i in 0..5 {
+            assert_eq!(Some(i), var.get(i).copied());
+            assert_eq!(Some(i), var.get_mut(i).copied());
+        }
+    }
 }