diff --git a/test/push-iterate-const-constexpr.cpp b/test/push-iterate-const-constexpr.cpp
new file mode 100644
index 0000000..2deb805
--- /dev/null
+++ b/test/push-iterate-const-constexpr.cpp
@@ -0,0 +1,51 @@
+#include <array>
+#include <ring-buffer.h>
+
+template <typename T, size_t N>
+constexpr bool array_equal(const std::array<T, N>& a, const std::array<T, N>& b) {
+    for (size_t i = 0; i < N; i++) {
+        if (a[i] != b[i]) return false;
+    }
+
+    return true;
+}
+
+constexpr bool test() {
+    ring_buffer<int, 4> buf;
+    const ring_buffer<int, 4>& const_buf = buf;
+
+    buf.push_back(1);
+    buf.push_back(2);
+    buf.push_back(3);
+    buf.push_back(4);
+    buf.push_back(5);
+    buf.push_back(6);
+
+    {
+        std::array<int, 4> expected{3, 4, 5, 6};
+        std::array<int, 4> actual;
+        int actual_index = 0;
+        for (const int& i : const_buf) {
+            actual[actual_index++] = i;
+        }
+        if (!array_equal(actual, expected)) return false;
+    }
+
+    buf.push_back(7);
+
+    {
+        std::array<int, 4> expected{4, 5, 6, 7};
+        std::array<int, 4> actual;
+        int actual_index = 0;
+        for (const int& i : const_buf) {
+            actual[actual_index++] = i;
+        }
+        if (!array_equal(actual, expected)) return false;
+    }
+
+    return true;
+}
+
+static_assert(test());
+
+int main() {}
diff --git a/test/push-iterate-const.cpp b/test/push-iterate-const.cpp
new file mode 100644
index 0000000..fd83c57
--- /dev/null
+++ b/test/push-iterate-const.cpp
@@ -0,0 +1,35 @@
+#include <vector>
+#include <cassert>
+#include <ring-buffer.h>
+
+int main() {
+    ring_buffer<int, 4> buf;
+    const ring_buffer<int, 4>& const_buf = buf;
+
+    buf.push_back(1);
+    buf.push_back(2);
+    buf.push_back(3);
+    buf.push_back(4);
+    buf.push_back(5);
+    buf.push_back(6);
+
+    {
+        std::vector<int> expected{3, 4, 5, 6};
+        std::vector<int> actual;
+        for (const int& i : const_buf) {
+            actual.push_back(i);
+        }
+        assert(actual == expected);
+    }
+
+    buf.push_back(7);
+
+    {
+        std::vector<int> expected{4, 5, 6, 7};
+        std::vector<int> actual;
+        for (const int& i : const_buf) {
+            actual.push_back(i);
+        }
+        assert(actual == expected);
+    }
+}
diff --git a/test/push-iterate-constexpr.cpp b/test/push-iterate-constexpr.cpp
new file mode 100644
index 0000000..16e1ccc
--- /dev/null
+++ b/test/push-iterate-constexpr.cpp
@@ -0,0 +1,52 @@
+#include <array>
+#include <ring-buffer.h>
+
+template <typename T, size_t N>
+constexpr bool array_equal(const std::array<T, N>& a, const std::array<T, N>& b) {
+    for (size_t i = 0; i < N; i++) {
+        if (a[i] != b[i]) return false;
+    }
+
+    return true;
+}
+
+constexpr bool test() {
+    ring_buffer<int, 4> buf;
+
+    buf.push_back(1);
+    buf.push_back(2);
+    buf.push_back(3);
+    buf.push_back(4);
+    buf.push_back(5);
+    buf.push_back(6);
+
+    {
+        std::array<int, 4> expected{13, 14, 15, 16};
+        std::array<int, 4> actual;
+        int actual_index = 0;
+        for (int& i : buf) {
+            i += 10;
+            actual[actual_index++] = i;
+        }
+        if (!array_equal(actual, expected)) return false;
+    }
+
+    buf.push_back(7);
+
+    {
+        std::array<int, 4> expected{24, 25, 26, 17};
+        std::array<int, 4> actual;
+        int actual_index = 0;
+        for (int& i : buf) {
+            i += 10;
+            actual[actual_index++] = i;
+        }
+        if (!array_equal(actual, expected)) return false;
+    }
+
+    return true;
+}
+
+static_assert(test());
+
+int main() {}
diff --git a/test/push-iterate.cpp b/test/push-iterate.cpp
new file mode 100644
index 0000000..71397d5
--- /dev/null
+++ b/test/push-iterate.cpp
@@ -0,0 +1,36 @@
+#include <vector>
+#include <cassert>
+#include <ring-buffer.h>
+
+int main() {
+    ring_buffer<int, 4> buf;
+
+    buf.push_back(1);
+    buf.push_back(2);
+    buf.push_back(3);
+    buf.push_back(4);
+    buf.push_back(5);
+    buf.push_back(6);
+
+    {
+        std::vector<int> expected{13, 14, 15, 16};
+        std::vector<int> actual;
+        for (int& i : buf) {
+            i += 10;
+            actual.push_back(i);
+        }
+        assert(actual == expected);
+    }
+
+    buf.push_back(7);
+
+    {
+        std::vector<int> expected{24, 25, 26, 17};
+        std::vector<int> actual;
+        for (int& i : buf) {
+            i += 10;
+            actual.push_back(i);
+        }
+        assert(actual == expected);
+    }
+}
diff --git a/test/simple.cpp b/test/simple.cpp
deleted file mode 100644
index 08f44ce..0000000
--- a/test/simple.cpp
+++ /dev/null
@@ -1,25 +0,0 @@
-#include <iostream>
-#include <ring-buffer.h>
-
-int main() {
-    ring_buffer<int, 4> buf;
-
-    buf.push_back(1);
-    buf.push_back(2);
-    buf.push_back(3);
-    buf.push_back(4);
-    buf.push_back(5);
-    buf.push_back(6);
-
-    std::cout << "before\n";
-    for (int& i : buf) {
-        std::cout << i << "\n";
-    }
-
-    buf.push_back(7);
-
-    std::cout << "after\n";
-    for (int& i : buf) {
-        std::cout << i << "\n";
-    }
-}