Very quick implementation for day 1

2021/src/lib.rs

@@ -88,3 +88,10 @@ pub fn get_implementation(day: usize, part2: bool) -> Solution {
         }
     }
 }
+
+#[cfg(test)]
+fn test_implementation(solution: Solution, data: impl AsRef<[u8]>, answer: impl ToString) {
+    let result = solution(&mut data.as_ref());
+
+    assert_eq!(answer.to_string(), result);
+}