feat: Add Option2 exercise (#290)

* added option2

* changed up the exercise, modified the help section

* Update exercises/option/option2.rs

Co-Authored-By: fmoko <mokou@posteo.net>

* Update exercises/option/option2.rs

Co-Authored-By: fmoko <mokou@posteo.net>

* Update exercises/option/option2.rs

Co-Authored-By: fmoko <mokou@posteo.net>

Co-authored-by: fmoko <mokou@posteo.net>

Author: sanjaykdragon

exercises/option/option2.rs

@@ -0,0 +1,25 @@
+// option2.rs
+// Make me compile! Execute `rustlings hint option2` for hints
+
+// I AM NOT DONE
+
+fn main() {
+    let optional_value = Some(String::from("rustlings"));
+    // Make this an if let statement whose value is "Some" type
+    value = optional_value {
+        println!("the value of optional value is: {}", value);
+    } else {
+        println!("The optional value doesn't contain anything!");
+    }
+
+    let mut optional_values_vec: Vec<Option<i8>> = Vec::new();
+    for x in 1..10 {
+        optional_values_vec.push(Some(x));
+    }
+
+    // make this a while let statement - remember that vector.pop also adds another layer of Option<T>
+    // You can stack `Option<T>`'s into while let and if let
+    value = optional_values_vec.pop() {
+        println!("current value: {}", value);
+    }
+}

info.toml

@@ -534,6 +534,21 @@ and:
 pattern matching
 """
 
+[[exercises]]
+name = "option2"
+path = "exercises/option/option2.rs"
+mode = "compile"
+hint = """
+check out:
+https://doc.rust-lang.org/rust-by-example/flow_control/if_let.html
+https://doc.rust-lang.org/rust-by-example/flow_control/while_let.html
+
+Remember that Options can be stacked in if let and while let.
+For example: Some(Some(variable)) = variable2
+
+
+"""
+
 [[exercises]]
 name = "result1"
 path = "exercises/error_handling/result1.rs"