3 files changed, 12 insertions, 0 deletions
diff --git a/src/frontier/image.rs b/src/frontier/image.rs
index 3655580..5642297 100644
--- a/src/frontier/image.rs
+++ b/src/frontier/image.rs
@@ -51,6 +51,10 @@ impl<C: ColorSpace> Frontier for ImageFrontier<C> {
         self.len - self.deleted
     }
 
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     fn place(&mut self, rgb8: Rgb8) -> Option<(u32, u32)> {
         let color = C::from(rgb8);
 
diff --git a/src/frontier/mean.rs b/src/frontier/mean.rs
index 889c5ba..6a32b97 100644
--- a/src/frontier/mean.rs
+++ b/src/frontier/mean.rs
@@ -129,6 +129,10 @@ impl<C: ColorSpace> Frontier for MeanFrontier<C> {
         self.len - self.deleted
     }
 
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     fn place(&mut self, rgb8: Rgb8) -> Option<(u32, u32)> {
         let color = C::from(rgb8);
         let (x, y) = self.forest.nearest(&color).map(|n| n.item.pos)?;
diff --git a/src/frontier/min.rs b/src/frontier/min.rs
index b22b290..269f3b7 100644
--- a/src/frontier/min.rs
+++ b/src/frontier/min.rs
@@ -136,6 +136,10 @@ impl<C: ColorSpace, R: Rng> Frontier for MinFrontier<C, R> {
         self.len - self.deleted
     }
 
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     fn place(&mut self, rgb8: Rgb8) -> Option<(u32, u32)> {
         let color = C::from(rgb8);
         let (x, y) = self