Merge fa6680ff76 into dd0634c483

errors6: Add alternative solution using From trait

README.md

@@ -45,6 +45,18 @@ cargo install rustlings
 
 </details>
 
+> [!CAUTION]
+> Don't try to clone the repository to do the exercises! `rust-analyzer` won't work in that case. Please follow the instructions above instead.
+> 
+> <details>
+> <summary>Why?</summary>
+>
+>The intended way to run Rustlings is to install the binary and run `rustlings init` as described in the installation/initialization sections. This generates a `Cargo.toml` (different than what you see in the repository) that includes each exercise as a separate binary target which is enough for `rust-analyzer` to work.
+>
+>If you just clone the repository and try to run and edit the exercises directly, the language server will not work.
+>
+> </details>
+
 ### Initialization
 
 After installing Rustlings, run the following command to initialize the `rustlings/` directory:

solutions/13_error_handling/errors6.rs

@@ -29,6 +29,21 @@ impl ParsePosNonzeroError {
     }
 }
 
+// As an alternative solution, implementing the `From` trait allows for the
+// automatic conversion from a `ParseIntError` into a `ParsePosNonzeroError`
+// using the `?` operator, without the need to call `map_err`.
+//
+// ```
+// let x: i64 = s.parse()?;
+// ```
+//
+// Traits like `From` will be dealt with in later exercises.
+impl From<ParseIntError> for ParsePosNonzeroError {
+    fn from(err: ParseIntError) -> Self {
+        ParsePosNonzeroError::ParseInt(err)
+    }
+}
+
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);