implement ToString for Image

src/main.rs

@@ -458,11 +458,13 @@ fn test_image_from_string() {
     assert_eq!(output, expected)
 }
 
-fn image_to_string(image: Image) -> String {
+impl ToString for Image {
+    #[inline]
+    fn to_string(&self) -> String {
         let mut string = String::new();
 
-    let sqrt = (image.pixels.len() as f64).sqrt() as usize; // 8 for SD, 16 for HD
+        let sqrt = (self.pixels.len() as f64).sqrt() as usize; // 8 for SD, 16 for HD
-    for line in image.pixels.chunks(sqrt) {
+        for line in self.pixels.chunks(sqrt) {
             for pixel in line {
                 string.push_str(&format!("{}", *pixel));
             }
@@ -472,13 +474,13 @@ fn image_to_string(image: Image) -> String {
         string.pop(); // remove trailing newline
 
         string
+    }
 }
 
 #[test]
 fn test_image_to_string() {
-    let output = image_to_string(example_image_chequers_1());
+    let output = example_image_chequers_1().to_string();
     let expected = include_str!("../test/resources/image-chequers-1").to_string();
-
     assert_eq!(output, expected);
 }
 
@@ -487,7 +489,7 @@ fn animation_frames_to_string(animation_frames: Vec<Image>) -> String {
     let last_frame = animation_frames.len() - 1;
 
     for (i, frame) in animation_frames.into_iter().enumerate() {
-        string.push_str(&image_to_string(frame));
+        string.push_str(&frame.to_string());
 
         if i < last_frame {
             string.push_str(&"\n>\n".to_string());