try_from_into solution

exercises/23_conversions/try_from_into.rs

@@ -1,9 +1,10 @@
-// TryFrom is a simple and safe type conversion that may fail in a controlled
-// way under some circumstances. Basically, this is the same as From. The main
-// difference is that this should return a Result type instead of the target
-// type itself. You can read more about it at
+// `TryFrom` is a simple and safe type conversion that may fail in a controlled
+// way under some circumstances. Basically, this is the same as `From`. The main
+// difference is that this should return a `Result` type instead of the target
+// type itself. You can read more about it in the documentation:
 // https://doc.rust-lang.org/std/convert/trait.TryFrom.html
 
+#![allow(clippy::useless_vec)]
 use std::convert::{TryFrom, TryInto};
 
 #[derive(Debug, PartialEq)]
@@ -13,7 +14,7 @@ struct Color {
     blue: u8,
 }
 
-// We will use this error type for these `TryFrom` conversions.
+// We will use this error type for the `TryFrom` conversions.
 #[derive(Debug, PartialEq)]
 enum IntoColorError {
     // Incorrect length of slice
@@ -22,78 +23,67 @@ enum IntoColorError {
     IntConversion,
 }
 
-// Your task is to complete this implementation and return an Ok result of inner
-// type Color. You need to create an implementation for a tuple of three
-// integers, an array of three integers, and a slice of integers.
-//
-// Note that the implementation for tuple and array will be checked at compile
-// time, but the slice implementation needs to check the slice length! Also note
-// that correct RGB color values must be integers in the 0..=255 range.
-
-// Tuple implementation
+// TODO: Tuple implementation.
+// Correct RGB color values must be integers in the 0..=255 range.
 impl TryFrom<(i16, i16, i16)> for Color {
     type Error = IntoColorError;
-    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
-    }
+
+    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
 }
 
-// Array implementation
+// TODO: Array implementation.
 impl TryFrom<[i16; 3]> for Color {
     type Error = IntoColorError;
-    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
-    }
+
+    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
 }
 
-// Slice implementation
+// TODO: Slice implementation.
+// This implementation needs to check the slice length.
 impl TryFrom<&[i16]> for Color {
     type Error = IntoColorError;
-    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
-    }
+
+    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
 }
 
 fn main() {
-    // Use the `try_from` function
+    // Using the `try_from` function.
     let c1 = Color::try_from((183, 65, 14));
-    println!("{:?}", c1);
+    println!("{c1:?}");
 
-    // Since TryFrom is implemented for Color, we should be able to use TryInto
+    // Since `TryFrom` is implemented for `Color`, we can use `TryInto`.
     let c2: Result<Color, _> = [183, 65, 14].try_into();
-    println!("{:?}", c2);
+    println!("{c2:?}");
 
     let v = vec![183, 65, 14];
-    // With slice we should use `try_from` function
+    // With slice we should use the `try_from` function
     let c3 = Color::try_from(&v[..]);
-    println!("{:?}", c3);
-    // or take slice within round brackets and use TryInto
+    println!("{c3:?}");
+    // or put the slice within round brackets and use `try_into`.
     let c4: Result<Color, _> = (&v[..]).try_into();
-    println!("{:?}", c4);
+    println!("{c4:?}");
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use IntoColorError::*;
 
     #[test]
     fn test_tuple_out_of_range_positive() {
-        assert_eq!(
-            Color::try_from((256, 1000, 10000)),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from((256, 1000, 10000)), Err(IntConversion));
     }
+
     #[test]
     fn test_tuple_out_of_range_negative() {
-        assert_eq!(
-            Color::try_from((-1, -10, -256)),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from((-1, -10, -256)), Err(IntConversion));
     }
+
     #[test]
     fn test_tuple_sum() {
-        assert_eq!(
-            Color::try_from((-1, 255, 255)),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from((-1, 255, 255)), Err(IntConversion));
     }
+
     #[test]
     fn test_tuple_correct() {
         let c: Result<Color, _> = (183, 65, 14).try_into();
@@ -103,25 +93,29 @@ mod tests {
             Color {
                 red: 183,
                 green: 65,
-                blue: 14
+                blue: 14,
             }
         );
     }
+
     #[test]
     fn test_array_out_of_range_positive() {
         let c: Result<Color, _> = [1000, 10000, 256].try_into();
-        assert_eq!(c, Err(IntoColorError::IntConversion));
+        assert_eq!(c, Err(IntConversion));
     }
+
     #[test]
     fn test_array_out_of_range_negative() {
         let c: Result<Color, _> = [-10, -256, -1].try_into();
-        assert_eq!(c, Err(IntoColorError::IntConversion));
+        assert_eq!(c, Err(IntConversion));
     }
+
     #[test]
     fn test_array_sum() {
         let c: Result<Color, _> = [-1, 255, 255].try_into();
-        assert_eq!(c, Err(IntoColorError::IntConversion));
+        assert_eq!(c, Err(IntConversion));
     }
+
     #[test]
     fn test_array_correct() {
         let c: Result<Color, _> = [183, 65, 14].try_into();
@@ -135,30 +129,25 @@ mod tests {
             }
         );
     }
+
     #[test]
     fn test_slice_out_of_range_positive() {
         let arr = [10000, 256, 1000];
-        assert_eq!(
-            Color::try_from(&arr[..]),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
     }
+
     #[test]
     fn test_slice_out_of_range_negative() {
         let arr = [-256, -1, -10];
-        assert_eq!(
-            Color::try_from(&arr[..]),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
     }
+
     #[test]
     fn test_slice_sum() {
         let arr = [-1, 255, 255];
-        assert_eq!(
-            Color::try_from(&arr[..]),
-            Err(IntoColorError::IntConversion)
-        );
+        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
     }
+
     #[test]
     fn test_slice_correct() {
         let v = vec![183, 65, 14];
@@ -169,18 +158,20 @@ mod tests {
             Color {
                 red: 183,
                 green: 65,
-                blue: 14
+                blue: 14,
             }
         );
     }
+
     #[test]
     fn test_slice_excess_length() {
         let v = vec![0, 0, 0, 0];
-        assert_eq!(Color::try_from(&v[..]), Err(IntoColorError::BadLen));
+        assert_eq!(Color::try_from(&v[..]), Err(BadLen));
     }
+
     #[test]
     fn test_slice_insufficient_length() {
         let v = vec![0, 0];
-        assert_eq!(Color::try_from(&v[..]), Err(IntoColorError::BadLen));
+        assert_eq!(Color::try_from(&v[..]), Err(BadLen));
     }
 }