diff --git a/Chapter04/01_static_assert/main.cpp b/Chapter04/01_static_assert/main.cpp
index 5fa5c8c1..3d69136d 100644
--- a/Chapter04/01_static_assert/main.cpp
+++ b/Chapter04/01_static_assert/main.cpp
@@ -1,20 +1,35 @@
 #include <cstring>
 #include <boost/array.hpp>
 
+// C++17 has std::byte out of the box!
+// Unfortunately this is as C++03 example.
+typedef unsigned char byte_t;
+
 template <class T, std::size_t BufSizeV>
-void serialize_bad(const T& value, boost::array<unsigned char, BufSizeV>& buffer) {
+void serialize_bad(const T& value, boost::array<byte_t, BufSizeV>& buffer) {
+    // TODO: check buffer size.
+    std::memcpy(&buffer[0], &value, sizeof(value));
+}
+
+namespace example2 {
+
+template <class T, std::size_t BufSizeV>
+void serialize_bad(const T& value, boost::array<byte_t, BufSizeV>& buffer) {
+    // TODO: think of something better.
     assert(BufSizeV >= sizeof(value));
-    // TODO: fixme
     std::memcpy(&buffer[0], &value, sizeof(value));
 }
 
+} // namespace example 2
+
+
 #include <boost/static_assert.hpp>
-#include <boost/type_traits/is_pod.hpp>
+#include <boost/type_traits/has_trivial_copy.hpp>
 
 template <class T, std::size_t BufSizeV>
-void serialize(const T& value, boost::array<unsigned char, BufSizeV>& buffer) {
+void serialize(const T& value, boost::array<byte_t, BufSizeV>& buffer) {
     BOOST_STATIC_ASSERT(BufSizeV >= sizeof(value));
-    BOOST_STATIC_ASSERT(boost::is_pod<T>::value);
+    BOOST_STATIC_ASSERT(boost::has_trivial_copy<T>::value);
 
     std::memcpy(&buffer[0], &value, sizeof(value));
 }
@@ -51,18 +66,21 @@ void type_traits_examples(T1& /*v1*/, T2& /*v2*/) {
     // int const volatile => int volatile
     // const int& => const int&
     typedef typename boost::remove_const<T1>::type t1_nonconst_t;
+
+    t1_nonconst_t value;
+    (void)value;
 }
 
 template <class T, std::size_t BufSizeV>
-void serialize2(const T& value, boost::array<unsigned char, BufSizeV>& buf) {
-    BOOST_STATIC_ASSERT_MSG(boost::is_pod<T>::value,
+void serialize2(const T& value, boost::array<byte_t, BufSizeV>& buf) {
+    BOOST_STATIC_ASSERT_MSG(boost::has_trivial_copy<T>::value,
         "This serialize2 function may be used only "
-        "with POD types."
+        "with trivially copyable types."
     );
 
     BOOST_STATIC_ASSERT_MSG(BufSizeV >= sizeof(value),
         "Can not fit value to buffer. "
-        "Make buffer bigger."
+        "Make the buffer bigger."
     );
 
     std::memcpy(&buf[0], &value, sizeof(value));
@@ -74,6 +92,10 @@ int main() {
 
     // Somewhere in code:
     boost::array<unsigned char, 1> buf;
+    serialize_bad('1', buf);
+    example2::serialize_bad('1', buf);
+    serialize('1', buf);
+    serialize2('2', buf);
     //serialize2(std::string("Hello word"), buf);
 
     (void)buf;