concepts: Add alternative Post implementation with states as types

[learn-rust.git] / concepts / src / main.rs

diff --git a/concepts/src/main.rs b/concepts/src/main.rs
index 94bdb960aa7e79b80d4ad22f082ab2822e6c1fbc..4b6df6447be9930e5773202f24601cd817722eb8 100644 (file)
--- a/concepts/src/main.rs
+++ b/concepts/src/main.rs
@@ -247,6 +247,42 @@ fn test_threads() {
     println!("counter: {}", *counter.lock().unwrap());
 }
 
+fn test_dyn_traits() {
+    let text = "I ate a salad for lunch today";
+    let mut post = Post::new();
+    post.add_text(text);
+    assert_eq!("", post.content());
+
+    post.request_review();
+    assert_eq!("", post.content());
+
+    post.reject();
+    assert_eq!("", post.content());
+
+    post.request_review();
+    assert_eq!("", post.content());
+
+    post.approve();  // first
+    assert_eq!("", post.content());
+
+    post.approve();  // second
+    assert_eq!(text, post.content());
+
+    post.reject();  // no-op
+    assert_eq!(text, post.content());
+}
+
+fn test_state_types() {
+    let mut post = TPost::new();
+    post.add_text("I ate a salad for lunch");
+    let post = post.request_review();
+    let mut post = post.reject();
+    post.add_text(" today");
+    let post = post.request_review();
+    let post = post.approve();
+    assert_eq!(post.content(), "I ate a salad for lunch today");
+}
+
 fn main() {
     test_strings();
     test_vectors();
@@ -256,4 +292,6 @@ fn main() {
     test_closures();
     test_iterators();
     test_threads();
+    test_dyn_traits();
+    test_state_types();
 }