add container, with placeholder iterator

Sponsored-by: author

separate iterator for container items

Sponsored-by: author

implement iterator

Sponsored-by: author
Sponsored-by: NLnet Foundation; NGI Assure
Sponsored-by: pep.foundation

1 files changed, 51 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index e7a11a9..6f9a675 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,53 @@
 fn main() {
-    println!("Hello, world!");
+    let mut cont: Container<usize> = Container::new();
+    cont.push(42);
+    for v in cont.iter() {
+        println!("{}", v);
+    }
+}
+
+struct Container<T> {
+    items: Vec<T>,
+}
+
+impl<T> Container<T> {
+    fn new() -> Self {
+        Self { items: vec![] }
+    }
+
+    fn push(&mut self, item: T) {
+        self.items.push(item);
+    }
+
+    fn iter<'a>(&'a self) -> ContainerItems<'a, T> {
+        ContainerItems::new(self)
+    }
+}
+
+struct ContainerItems<'a, T> {
+    cont: &'a Container<T>,
+    next: Option<usize>,
+}
+
+impl<'a, T> ContainerItems<'a, T> {
+    fn new(cont: &'a Container<T>) -> Self {
+        Self { cont, next: Some(0) }
+    }
+}
+
+impl<'a, T> Iterator for ContainerItems<'a, T> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(i) = self.next {
+            if i < self.cont.items.len() {
+                self.next = Some(i + 1);
+                Some(&self.cont.items[i])
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    }
 }