1 files changed, 8 insertions, 1 deletions
diff --git a/lvc/src/impls.rs b/lvc/src/impls.rs
index 04699c6..098db39 100644
--- a/lvc/src/impls.rs
+++ b/lvc/src/impls.rs
@@ -1,5 +1,5 @@
 use crate::{Frame, Pixel, Ref, View, P2};
-use std::ops::{Add, Index, IndexMut, Sub};
+use std::ops::{Add, AddAssign, Index, IndexMut, Sub};
 
 impl Frame {
     pub fn export(&self, view: View) -> Vec<Pixel> {
@@ -18,6 +18,7 @@ impl Frame {
                 source = &source[1..];
             }
         }
+        assert_eq!(source.len(), 0)
     }
     pub fn new(size: P2) -> Self {
         Self {
@@ -39,6 +40,12 @@ impl Pixel {
     pub const GREEN: Pixel = Pixel { r: 0, g: 255, b: 0 };
     pub const BLUE: Pixel = Pixel { r: 0, g: 0, b: 255 };
 }
+impl AddAssign for P2 {
+    fn add_assign(&mut self, rhs: Self) {
+        self.x += rhs.x;
+        self.y += rhs.y;
+    }
+}
 impl Add for Pixel {
     type Output = Pixel;
     #[inline]