Auto merge of #163 - briankung:add_structs, r=komaeda

Adds a simple exercise for structures

Thanks for rustlings! Here's a small contribution in return.

exercises/structs/README.md

@@ -0,0 +1,7 @@
+### Strings
+
+Rust has three struct types: a classic c struct, a tuple struct, and a unit struct.
+
+#### Book Sections
+
+- [Structures](https://doc.rust-lang.org/rust-by-example/custom_types/structs.html)

exercises/structs/structs1.rs

@@ -0,0 +1,46 @@
+// structs1.rs
+// Address all the TODOs to make the tests pass!
+
+struct ColorClassicStruct {
+    // TODO: Something goes here
+}
+
+struct ColorTupleStruct(/* TODO: Something goes here */);
+
+struct ColorUnitStruct;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn classic_c_structs() {
+        // TODO: Instantiate a classic c struct!
+        // let green =
+
+        assert_eq!(green.name, "green");
+        assert_eq!(green.hex, "#00FF00");
+    }
+
+    #[test]
+    fn tuple_structs() {
+        // TODO: Instantiate a tuple struct!
+        // For more fun, use the field initialization shorthand.
+        // let green =
+
+        assert_eq!(green.0, "green");
+        assert_eq!(green.1, "#00FF00");
+    }
+
+    #[test]
+    fn unit_structs() {
+        // TODO: Instantiate a unit struct!
+        // let green =
+
+        if let ColorUnitStruct = green {
+            assert!(true);
+        } else {
+            assert!(false);
+        }
+    }
+}

info.toml

@@ -76,6 +76,12 @@ mode = "compile"
 path = "exercises/primitive_types/primitive_types6.rs"
 mode = "compile"
 
+# STRUCTS
+
+[[exercises]]
+path = "exercises/structs/structs1.rs"
+mode = "test"
+
 # TESTS
 
 [[exercises]]