update polygon impl to work with the multiple versions of rstar we no…

…w support

geo-types/src/polygon.rs

@@ -543,14 +543,24 @@ impl<T: AbsDiffEq<Epsilon = T> + CoordNum> AbsDiffEq for Polygon<T> {
     }
 }
 
-#[cfg(feature = "rstar")]
-impl<T> ::rstar::RTreeObject for Polygon<T>
-where
-    T: ::num_traits::Float + ::rstar::RTreeNum,
-{
-    type Envelope = ::rstar::AABB<Point<T>>;
+#[cfg(any(feature = "rstar_0_8", feature = "rstar_0_9"))]
+macro_rules! impl_rstar_polygon {
+    ($rstar:ident) => {
+        impl<T> $rstar::RTreeObject for Polygon<T>
+        where
+            T: ::num_traits::Float + ::$rstar::RTreeNum,
+        {
+            type Envelope = ::$rstar::AABB<Point<T>>;
 
-    fn envelope(&self) -> Self::Envelope {
-        self.exterior.envelope()
-    }
+            fn envelope(&self) -> Self::Envelope {
+                self.exterior.envelope()
+            }
+        }
+    };
 }
+
+#[cfg(feature = "rstar_0_8")]
+impl_rstar_polygon!(rstar_0_8);
+
+#[cfg(feature = "rstar_0_9")]
+impl_rstar_polygon!(rstar_0_9);