strings2 solution

solutions/09_strings/strings2.rs

@@ -1 +1,15 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+fn is_a_color_word(attempt: &str) -> bool {
+    attempt == "green" || attempt == "blue" || attempt == "red"
+}
+
+fn main() {
+    let word = String::from("green");
+
+    if is_a_color_word(&word) {
+        //             ^ added to have `&String` which is automatically
+        //               coerced to `&str` by the compiler.
+        println!("That is a color word I know!");
+    } else {
+        println!("That is not a color word I know.");
+    }
+}