diff --git a/example/cpp03/class_intrusive.cpp b/example/cpp03/class_intrusive.cpp
index 64a3956e..dc27f0af 100644
--- a/example/cpp03/class_intrusive.cpp
+++ b/example/cpp03/class_intrusive.cpp
@@ -21,8 +21,7 @@
 #include <sstream>
 #include <cassert>
 
-// msgpack.hpp is also ok
-#include <msgpack_fwd.hpp>
+#include <msgpack.hpp>
 
 
 class my_class {
@@ -57,8 +56,6 @@ void print(std::string const& buf) {
     std::cout << std::dec << std::endl;
 }
 
-#include <msgpack.hpp>
-
 int main() {
     {   // pack, unpack
         my_class my("John Smith", 42);
diff --git a/example/cpp03/class_non_intrusive.cpp b/example/cpp03/class_non_intrusive.cpp
index 1168b484..5a60ca36 100644
--- a/example/cpp03/class_non_intrusive.cpp
+++ b/example/cpp03/class_non_intrusive.cpp
@@ -21,27 +21,6 @@
 #include <sstream>
 #include <cassert>
 
-// msgpack.hpp should be included at after user declarations
-#include <msgpack_fwd.hpp>
-
-
-// declarations
-class my_class;
-
-namespace msgpack {
-
-MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
-
-object const& operator>> (msgpack::object const& o, my_class& v);
-
-template <typename Stream>
-packer<Stream>& operator<< (msgpack::packer<Stream>& o, my_class const& v);
-
-void operator<< (msgpack::object::with_zone& o, my_class const& v);
-
-} // MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS)
-} // namespace msgpack
-
 #include <msgpack.hpp>
 
 class my_class {
@@ -63,40 +42,48 @@ private:
     int age_;
 };
 
-
-// definitions
-
+// User defined class template specialization
 namespace msgpack {
-
 MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
+namespace adaptor {
 
-inline object const& operator>> (msgpack::object const& o, my_class& v) {
-    if (o.type != msgpack::type::ARRAY) throw msgpack::type_error();
-    if (o.via.array.size != 2) throw msgpack::type_error();
-    v = my_class(
-        o.via.array.ptr[0].as<std::string>(),
-        o.via.array.ptr[1].as<int>());
-    return o;
-}
+template<>
+struct convert<my_class> {
+    msgpack::object const& operator()(msgpack::object const& o, my_class& v) const {
+        if (o.type != msgpack::type::ARRAY) throw msgpack::type_error();
+        if (o.via.array.size != 2) throw msgpack::type_error();
+        v = my_class(
+            o.via.array.ptr[0].as<std::string>(),
+            o.via.array.ptr[1].as<int>());
+        return o;
+    }
+};
 
+template<>
+struct pack<my_class> {
+    template <typename Stream>
+    packer<Stream>& operator()(msgpack::packer<Stream>& o, my_class const& v) const {
+        // packing member variables as an array.
+        o.pack_array(2);
+        o.pack(v.get_name());
+        o.pack(v.get_age());
+        return o;
+    }
+};
 
-template <typename Stream>
-inline packer<Stream>& operator<< (msgpack::packer<Stream>& o, my_class const& v) {
-    // packing member variables as an array.
-    o.pack_array(2);
-    o.pack(v.get_name());
-    o.pack(v.get_age());
-    return o;
-}
-
-inline void operator<< (msgpack::object::with_zone& o, my_class const& v) {
-    o.type = type::ARRAY;
-    o.via.array.size = 2;
-    o.via.array.ptr = static_cast<object*>(o.zone.allocate_align(sizeof(object) * o.via.array.size));
-    o.via.array.ptr[0] = msgpack::object(v.get_name(), o.zone);
-    o.via.array.ptr[1] = msgpack::object(v.get_age(), o.zone);
-}
+template <>
+struct object_with_zone<my_class> {
+    void operator()(msgpack::object::with_zone& o, my_class const& v) const {
+        o.type = type::ARRAY;
+        o.via.array.size = 2;
+        o.via.array.ptr = static_cast<msgpack::object*>(
+            o.zone.allocate_align(sizeof(msgpack::object) * o.via.array.size));
+        o.via.array.ptr[0] = msgpack::object(v.get_name(), o.zone);
+        o.via.array.ptr[1] = msgpack::object(v.get_age(), o.zone);
+    }
+};
 
+} // namespace adaptor
 } // MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS)
 } // namespace msgpack
 
diff --git a/example/cpp03/enum.cpp b/example/cpp03/enum.cpp
index c87dd516..2f8f505f 100644
--- a/example/cpp03/enum.cpp
+++ b/example/cpp03/enum.cpp
@@ -15,11 +15,12 @@
 //    limitations under the License.
 //
 
-#include <msgpack_fwd.hpp>
 #include <sstream>
 #include <iostream>
 #include <cassert>
 
+#include <msgpack.hpp>
+
 enum my_enum {
     elem1,
     elem2,
@@ -28,8 +29,6 @@ enum my_enum {
 
 MSGPACK_ADD_ENUM(my_enum);
 
-#include <msgpack.hpp>
-
 int main(void)
 {
     {   // pack, unpack
diff --git a/example/cpp03/protocol.cpp b/example/cpp03/protocol.cpp
index b4462f5b..5b8a06e3 100644
--- a/example/cpp03/protocol.cpp
+++ b/example/cpp03/protocol.cpp
@@ -20,6 +20,8 @@
 #include <iostream>
 #include <sstream>
 
+// This example uses obsolete APIs
+// See protocol_new.cpp
 namespace myprotocol {
     using namespace msgpack::type;
     using msgpack::define;