Update

assets/dash-3d-implementation/undefined-behaviour-error.txt

@@ -0,0 +1,10 @@
+error[E0502]: cannot borrow `vec` as mutable because it is also borrowed as immutable
+ --> src/main.rs:4:9
+  |
+3 |     for value in &vec {
+  |                  ----
+  |                  |
+  |                  immutable borrow occurs here
+  |                  immutable borrow later used here
+4 |         vec.push(*value);
+  |         ^^^^^^^^^^^^^^^^ mutable borrow occurs here

assets/dash-3d-implementation/undefined-behaviour-it.cpp

@@ -0,0 +1,3 @@
+auto vec = std::vector<int> {1, 2, 3};
+for (auto it = std::begin(vec); it < std::end(vec); it++)
+    vec.push_back(*it);

assets/dash-3d-implementation/undefined-behaviour-it.rs

@@ -0,0 +1,10 @@
+fn func() {
+    let mut vec = vec![1, 2, 3];
+    let iter = vec.iter();
+    loop {
+        match iter.next() {
+            Some(x) => vec.push(x),
+            None => break,
+        }
+    }
+}

assets/dash-3d-implementation/undefined-behaviour.cpp

@@ -0,0 +1,3 @@
+auto vec = std::vector<int> {1, 2, 3};
+for (auto value: vec)
+    vec.push_back(value);

assets/dash-3d-implementation/undefined-behaviour.rs

@@ -0,0 +1,6 @@
+fn func() {
+    let mut vec = vec![1, 2, 3];
+    for value in &vec {
+        vec.push(value);
+    }
+}