From 0465243c710ede74a78885077140d8673efbc647 Mon Sep 17 00:00:00 2001
From: Determinant <tederminant@gmail.com>
Date: Fri, 20 Jul 2018 20:08:59 -0400
Subject: improve msg & msg network interface

---
 include/salticidae/msg.h     |  56 ++-------
 include/salticidae/network.h | 263 +++++++++++++++++++++++++++----------------
 include/salticidae/ref.h     |  19 ++--
 3 files changed, 180 insertions(+), 158 deletions(-)

(limited to 'include')

diff --git a/include/salticidae/msg.h b/include/salticidae/msg.h
index 33f0d2b..8a63a50 100644
--- a/include/salticidae/msg.h
+++ b/include/salticidae/msg.h
@@ -36,14 +36,10 @@
 
 namespace salticidae {
 
-template<typename OpcodeType = uint8_t,
-        const OpcodeType PING = 0xf0,
-        const OpcodeType PONG = 0xf1>
+template<typename OpcodeType>
 class MsgBase {
     public:
     using opcode_t = OpcodeType;
-    static const opcode_t OPCODE_PING;
-    static const opcode_t OPCODE_PONG;
     static const size_t header_size;
 
     private:
@@ -195,32 +191,6 @@ class MsgBase {
         return std::move(s);
     }
 
-    void gen_ping(uint16_t port) {
-        DataStream s;
-        set_opcode(OPCODE_PING);
-        s << htole(port);
-        set_payload(std::move(s));
-    }
-
-    void parse_ping(uint16_t &port) const {
-        DataStream s(get_payload());
-        s >> port;
-        port = letoh(port);
-    }
-
-    void gen_pong(uint16_t port) {
-        DataStream s;
-        set_opcode(OPCODE_PONG);
-        s << htole(port);
-        set_payload(std::move(s));
-    }
-
-    void parse_pong(uint16_t &port) const {
-        DataStream s(get_payload());
-        s >> port;
-        port = letoh(port);
-    }
-
     void gen_hash_list(DataStream &s,
                         const std::vector<uint256_t> &hashes) {
         uint32_t size = htole((uint32_t)hashes.size());
@@ -242,24 +212,12 @@ class MsgBase {
 
 };
 
-template<typename OpcodeType,
-        OpcodeType _,
-        OpcodeType __>
-const size_t MsgBase<OpcodeType, _, __>::header_size =
-    sizeof(MsgBase<OpcodeType, _, __>::magic) +
-    sizeof(MsgBase<OpcodeType, _, __>::opcode) +
-    sizeof(MsgBase<OpcodeType, _, __>::length) +
-    sizeof(MsgBase<OpcodeType, _, __>::checksum);
-
-template<typename OpcodeType,
-        OpcodeType PING,
-        OpcodeType _>
-const OpcodeType MsgBase<OpcodeType, PING, _>::OPCODE_PING = PING;
-
-template<typename OpcodeType,
-        OpcodeType _,
-        OpcodeType PONG>
-const OpcodeType MsgBase<OpcodeType, _, PONG>::OPCODE_PONG = PONG;
+template<typename OpcodeType>
+const size_t MsgBase<OpcodeType>::header_size =
+    sizeof(MsgBase<OpcodeType>::magic) +
+    sizeof(MsgBase<OpcodeType>::opcode) +
+    sizeof(MsgBase<OpcodeType>::length) +
+    sizeof(MsgBase<OpcodeType>::checksum);
 
 }
 
diff --git a/include/salticidae/network.h b/include/salticidae/network.h
index 0ea7455..1e0f560 100644
--- a/include/salticidae/network.h
+++ b/include/salticidae/network.h
@@ -32,16 +32,51 @@
 
 namespace salticidae {
 
+template<typename ClassType, typename ReturnType, typename... Args, typename... FArgs>
+inline auto handler_bind(ReturnType(ClassType::* f)(Args...), FArgs&&... fargs) {
+    return std::function<ReturnType(Args...)>(std::bind(f, std::forward<FArgs>(fargs)...));
+}
+
 /** Network of nodes who can send async messages.  */
-template<typename MsgType>
+template<typename OpcodeType>
 class MsgNetwork: public ConnPool {
     public:
+    using Msg = MsgBase<OpcodeType>;
+    /* match lambdas */
+    template<typename T>
+    struct callback_traits:
+        public callback_traits<decltype(&T::operator())> {};
+    
+    /* match plain functions */
+    template<typename ReturnType, typename MsgType, typename ConnType>
+    struct callback_traits<ReturnType(MsgType, ConnType)> {
+        using ret_type = ReturnType;
+        using conn_type = ConnType;
+        using msg_type = typename std::remove_reference<MsgType>::type;
+    };
+    
+    /* match function pointers */
+    template<typename ReturnType, typename... Args>
+    struct callback_traits<ReturnType(*)(Args...)>:
+        public callback_traits<ReturnType(Args...)> {};
+    
+    /* match const member functions */
+    template<typename ClassType, typename ReturnType, typename... Args>
+    struct callback_traits<ReturnType(ClassType::*)(Args...) const>:
+        public callback_traits<ReturnType(Args...)> {};
+    
+    /* match member functions */
+    template<typename ClassType, typename ReturnType, typename... Args>
+    struct callback_traits<ReturnType(ClassType::*)(Args...)>:
+        public callback_traits<ReturnType(Args...)> {};
+
     class Conn: public ConnPool::Conn {
         enum MsgState {
             HEADER,
             PAYLOAD
         };
-        MsgType msg;
+
+        Msg msg;
         MsgState msg_state;
         MsgNetwork *mn;
 
@@ -74,13 +109,13 @@ class MsgNetwork: public ConnPool {
     };
 
     using conn_t = RcObj<Conn>;
-    using msg_callback_t = std::function<void(const MsgType &msg, conn_t conn)>;
+    using msg_callback_t = std::function<void(const Msg &msg, conn_t conn)>;
 #ifdef SALTICIDAE_MSG_STAT
     class msg_stat_by_opcode_t:
-            public std::unordered_map<typename MsgType::opcode_t,
+            public std::unordered_map<typename Msg::opcode_t,
                                         std::pair<uint32_t, size_t>> {
         public:
-        void add(const MsgType &msg) {
+        void add(const Msg &msg) {
             auto &p = this->operator[](msg.get_opcode());
             p.first++;
             p.second += msg.get_length();
@@ -89,7 +124,7 @@ class MsgNetwork: public ConnPool {
 #endif
 
     private:
-    std::unordered_map<typename MsgType::opcode_t,
+    std::unordered_map<typename Msg::opcode_t,
                         msg_callback_t> handler_map;
 
     protected:
@@ -101,6 +136,7 @@ class MsgNetwork: public ConnPool {
     ConnPool::conn_t create_conn() override { return (new Conn(this))->self(); }
 
     public:
+
     MsgNetwork(const EventContext &eb,
             int max_listen_backlog,
             double conn_server_timeout,
@@ -109,7 +145,18 @@ class MsgNetwork: public ConnPool {
                     conn_server_timeout,
                     seg_buff_size) {}
 
-    void reg_handler(typename MsgType::opcode_t opcode, msg_callback_t handler);
+    template<typename Func>
+    typename std::enable_if<std::is_constructible<
+        typename callback_traits<Func>::msg_type, DataStream &&>::value>::type
+    reg_handler(Func handler) {
+        using callback_t = callback_traits<Func>;
+        handler_map[callback_t::msg_type::opcode] = [handler](const Msg &msg, conn_t conn) {
+            handler(typename callback_t::msg_type(msg.get_payload()),
+                    static_pointer_cast<typename callback_t::conn_type::type>(conn));
+        };
+    }
+
+    template<typename MsgType>
     void send_msg(const MsgType &msg, conn_t conn);
     using ConnPool::listen;
 #ifdef SALTICIDAE_MSG_STAT
@@ -126,9 +173,10 @@ class MsgNetwork: public ConnPool {
 };
 
 /** Simple network that handles client-server requests. */
-template<typename MsgType>
-class ClientNetwork: public MsgNetwork<MsgType> {
-    using MsgNet = MsgNetwork<MsgType>;
+template<typename OpcodeType>
+class ClientNetwork: public MsgNetwork<OpcodeType> {
+    using MsgNet = MsgNetwork<OpcodeType>;
+    using Msg = typename MsgNet::Msg;
     std::unordered_map<NetAddr, typename MsgNet::conn_t> addr2conn;
 
     public:
@@ -159,6 +207,7 @@ class ClientNetwork: public MsgNetwork<MsgType> {
                 conn_server_timeout,
                 seg_buff_size) {}
 
+    template<typename MsgType>
     void send_msg(const MsgType &msg, const NetAddr &addr);
     conn_t connect(const NetAddr &addr) = delete;
 };
@@ -169,9 +218,12 @@ class PeerNetworkError: public SalticidaeError {
 
 /** Peer-to-peer network where any two nodes could hold a bi-diretional message
  * channel, established by either side. */
-template<typename MsgType>
-class PeerNetwork: public MsgNetwork<MsgType> {
-    using MsgNet= MsgNetwork<MsgType>;
+template<typename OpcodeType = uint8_t,
+        OpcodeType OPCODE_PING = 0xf0,
+        OpcodeType OPCODE_PONG = 0xf1>
+class PeerNetwork: public MsgNetwork<OpcodeType> {
+    using MsgNet = MsgNetwork<OpcodeType>;
+    using Msg = typename MsgNet::Msg;
     public:
     enum IdentityMode {
         IP_BASED,
@@ -244,8 +296,34 @@ class PeerNetwork: public MsgNetwork<MsgType> {
     double conn_timeout;
     uint16_t listen_port;
 
-    void msg_ping(const MsgType &msg, ConnPool::conn_t conn);
-    void msg_pong(const MsgType &msg, ConnPool::conn_t conn);
+    struct MsgPing {
+        static const OpcodeType opcode;
+        DataStream serialized;
+        uint16_t port;
+        MsgPing(uint16_t port) {
+            serialized << htole(port);
+        }
+        MsgPing(DataStream &&s) {
+            s >> port;
+            port = letoh(port);
+        }
+    };
+
+    struct MsgPong {
+        static const OpcodeType opcode;
+        DataStream serialized;
+        uint16_t port;
+        MsgPong(uint16_t port) {
+            serialized << htole(port);
+        }
+        MsgPong(DataStream &&s) {
+            s >> port;
+            port = letoh(port);
+        }
+    };
+
+    void msg_ping(MsgPing &&msg, conn_t conn);
+    void msg_pong(MsgPong &&msg, conn_t conn);
     void reset_conn_timeout(conn_t conn);
     bool check_new_conn(conn_t conn, uint16_t port);
     void start_active_conn(const NetAddr &paddr);
@@ -275,7 +353,9 @@ class PeerNetwork: public MsgNetwork<MsgType> {
 
     void add_peer(const NetAddr &paddr);
     const conn_t get_peer_conn(const NetAddr &paddr) const;
+    template<typename MsgType>
     void send_msg(const MsgType &msg, const Peer *peer);
+    template<typename MsgType>
     void send_msg(const MsgType &msg, const NetAddr &paddr);
     void listen(NetAddr listen_addr);
     bool has_peer(const NetAddr &paddr) const;
@@ -285,18 +365,18 @@ class PeerNetwork: public MsgNetwork<MsgType> {
     }
 };
 
-template<typename MsgType>
-void MsgNetwork<MsgType>::Conn::on_read() {
+template<typename OpcodeType>
+void MsgNetwork<OpcodeType>::Conn::on_read() {
     auto &recv_buffer = read();
     auto conn = static_pointer_cast<Conn>(self());
     while (get_fd() != -1)
     {
         if (msg_state == Conn::HEADER)
         {
-            if (recv_buffer.size() < MsgType::header_size) break;
+            if (recv_buffer.size() < Msg::header_size) break;
             /* new header available */
-            bytearray_t data = recv_buffer.pop(MsgType::header_size);
-            msg = MsgType(data.data());
+            bytearray_t data = recv_buffer.pop(Msg::header_size);
+            msg = Msg(data.data());
             msg_state = Conn::PAYLOAD;
         }
         if (msg_state == Conn::PAYLOAD)
@@ -331,8 +411,8 @@ void MsgNetwork<MsgType>::Conn::on_read() {
     }
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Peer::reset_conn(conn_t new_conn) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Peer::reset_conn(conn_t new_conn) {
     if (conn != new_conn)
     {
         if (conn)
@@ -348,23 +428,21 @@ void PeerNetwork<MsgType>::Peer::reset_conn(conn_t new_conn) {
     clear_all_events();
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Conn::on_setup() {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Conn::on_setup() {
     assert(!ev_timeout);
     ev_timeout = Event(pn->eb, -1, 0, [this](evutil_socket_t, short) {
         SALTICIDAE_LOG_INFO("peer ping-pong timeout");
         this->terminate();
     });
     /* the initial ping-pong to set up the connection */
-    MsgType ping;
-    ping.gen_ping(pn->listen_port);
     auto conn = static_pointer_cast<Conn>(this->self());
     pn->reset_conn_timeout(conn);
-    pn->MsgNet::send_msg(ping, conn);
+    pn->MsgNet::send_msg(MsgPing(pn->listen_port), conn);
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Conn::on_teardown() {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Conn::on_teardown() {
     auto it = pn->id2peer.find(peer_id);
     if (it == pn->id2peer.end()) return;
     auto p = it->second.get();
@@ -383,8 +461,8 @@ void PeerNetwork<MsgType>::Conn::on_teardown() {
     p->ev_retry_timer.add_with_timeout(pn->gen_conn_timeout());
 }
 
-template<typename MsgType>
-bool PeerNetwork<MsgType>::check_new_conn(conn_t conn, uint16_t port) {
+template<typename O, O _, O __>
+bool PeerNetwork<O, _, __>::check_new_conn(conn_t conn, uint16_t port) {
     if (conn->peer_id.is_null())
     {   /* passive connections can eventually have ids after getting the port
            number in IP_BASED_PORT mode */
@@ -412,21 +490,18 @@ bool PeerNetwork<MsgType>::check_new_conn(conn_t conn, uint16_t port) {
     return false;
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::msg_ping(const MsgType &msg, ConnPool::conn_t conn_) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::msg_ping(MsgPing &&msg, conn_t conn_) {
     auto conn = static_pointer_cast<Conn>(conn_);
-    uint16_t port;
-    msg.parse_ping(port);
+    uint16_t port = msg.port;
     SALTICIDAE_LOG_INFO("ping from %s, port %u", std::string(*conn).c_str(), ntohs(port));
     if (check_new_conn(conn, port)) return;
     auto p = id2peer.find(conn->peer_id)->second.get();
-    MsgType pong;
-    pong.gen_pong(this->listen_port);
-    send_msg(pong, p);
+    send_msg(MsgPong(this->listen_port), p);
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::msg_pong(const MsgType &msg, ConnPool::conn_t conn_) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::msg_pong(MsgPong &&msg, conn_t conn_) {
     auto conn = static_pointer_cast<Conn>(conn_);
     auto it = id2peer.find(conn->peer_id);
     if (it == id2peer.end())
@@ -435,8 +510,7 @@ void PeerNetwork<MsgType>::msg_pong(const MsgType &msg, ConnPool::conn_t conn_)
         return;
     }
     auto p = it->second.get();
-    uint16_t port;
-    msg.parse_pong(port);
+    uint16_t port = msg.port;
     if (check_new_conn(conn, port)) return;
     p->pong_msg_ok = true;
     if (p->ping_timer_ok)
@@ -446,18 +520,16 @@ void PeerNetwork<MsgType>::msg_pong(const MsgType &msg, ConnPool::conn_t conn_)
     }
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::listen(NetAddr listen_addr) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::listen(NetAddr listen_addr) {
     MsgNet::listen(listen_addr);
     listen_port = listen_addr.port;
-    this->reg_handler(MsgType::OPCODE_PING,
-                        std::bind(&PeerNetwork::msg_ping, this, _1, _2));
-    this->reg_handler(MsgType::OPCODE_PONG,
-                        std::bind(&PeerNetwork::msg_pong, this, _1, _2));
+    this->reg_handler(handler_bind(&PeerNetwork::msg_ping, this, _1, _2));
+    this->reg_handler(handler_bind(&PeerNetwork::msg_pong, this, _1, _2));
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::start_active_conn(const NetAddr &addr) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::start_active_conn(const NetAddr &addr) {
     auto p = id2peer.find(addr)->second.get();
     if (p->connected) return;
     auto conn = static_pointer_cast<Conn>(connect(addr));
@@ -468,8 +540,8 @@ void PeerNetwork<MsgType>::start_active_conn(const NetAddr &addr) {
         conn->peer_id.port = 0;
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::add_peer(const NetAddr &addr) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::add_peer(const NetAddr &addr) {
     auto it = id2peer.find(addr);
     if (it != id2peer.end())
         throw PeerNetworkError("peer already exists");
@@ -478,28 +550,26 @@ void PeerNetwork<MsgType>::add_peer(const NetAddr &addr) {
     start_active_conn(addr);
 }
 
-template<typename MsgType>
-const typename PeerNetwork<MsgType>::conn_t
-PeerNetwork<MsgType>::get_peer_conn(const NetAddr &paddr) const {
+template<typename O, O _, O __>
+const typename PeerNetwork<O, _, __>::conn_t
+PeerNetwork<O, _, __>::get_peer_conn(const NetAddr &paddr) const {
     auto it = id2peer.find(paddr);
     if (it == id2peer.end())
         throw PeerNetworkError("peer does not exist");
     return it->second->conn;
 }
 
-template<typename MsgType>
-bool PeerNetwork<MsgType>::has_peer(const NetAddr &paddr) const {
+template<typename O, O _, O __>
+bool PeerNetwork<O, _, __>::has_peer(const NetAddr &paddr) const {
     return id2peer.count(paddr);
 }
 
+template<typename OpcodeType>
 template<typename MsgType>
-void MsgNetwork<MsgType>::reg_handler(typename MsgType::opcode_t opcode,
-                                        msg_callback_t handler) {
-    handler_map[opcode] = handler;
-}
-
-template<typename MsgType>
-void MsgNetwork<MsgType>::send_msg(const MsgType &msg, conn_t conn) {
+void MsgNetwork<OpcodeType>::send_msg(const MsgType &_msg, conn_t conn) {
+    Msg msg;
+    msg.set_opcode(MsgType::opcode);
+    msg.set_payload(std::move(_msg.serialized));
     bytearray_t msg_data = msg.serialize();
     SALTICIDAE_LOG_DEBUG("wrote message %s to %s",
                 std::string(msg).c_str(),
@@ -511,65 +581,53 @@ void MsgNetwork<MsgType>::send_msg(const MsgType &msg, conn_t conn) {
 #endif
 }
 
+template<typename O, O _, O __>
 template<typename MsgType>
-void PeerNetwork<MsgType>::send_msg(const MsgType &msg, const Peer *peer) {
-    bytearray_t msg_data = msg.serialize();
-    SALTICIDAE_LOG_DEBUG("wrote message %s to %s",
-                std::string(msg).c_str(),
-                std::string(peer->addr).c_str());
+void PeerNetwork<O, _, __>::send_msg(const MsgType &msg, const Peer *peer) {
     if (peer->connected)
-    {
-        SALTICIDAE_LOG_DEBUG("wrote to ConnPool");
-        peer->conn->write(std::move(msg_data));
-    }
+        MsgNet::send_msg(msg, peer->conn);
     else
-    {
         SALTICIDAE_LOG_DEBUG("dropped");
-    }
-#ifdef SALTICIDAE_MSG_STAT
-    peer->conn->nsent++;
-    this->sent_by_opcode.add(msg);
-#endif
 }
 
+template<typename O, O _, O __>
 template<typename MsgType>
-void PeerNetwork<MsgType>::send_msg(const MsgType &msg, const NetAddr &addr) {
+void PeerNetwork<O, _, __>::send_msg(const MsgType &msg, const NetAddr &addr) {
     auto it = id2peer.find(addr);
     if (it == id2peer.end())
     {
-        SALTICIDAE_LOG_ERROR("sending to non-existing peer: %s", std::string(addr).c_str());
+        SALTICIDAE_LOG_ERROR("sending to non-existing peer: %s",
+                            std::string(addr).c_str());
         throw PeerNetworkError("peer does not exist");
     }
     send_msg(msg, it->second.get());
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Peer::reset_ping_timer() {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Peer::reset_ping_timer() {
     assert(ev_ping_timer);
     ev_ping_timer.del();
     ev_ping_timer.add_with_timeout(gen_rand_timeout(pn->ping_period));
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::reset_conn_timeout(conn_t conn) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::reset_conn_timeout(conn_t conn) {
     assert(conn->ev_timeout);
     conn->ev_timeout.del();
     conn->ev_timeout.add_with_timeout(conn_timeout);
     SALTICIDAE_LOG_INFO("reset timeout %.2f", conn_timeout);
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Peer::send_ping() {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Peer::send_ping() {
     ping_timer_ok = false;
     pong_msg_ok = false;
-    MsgType ping;
-    ping.gen_ping(pn->listen_port);
     pn->reset_conn_timeout(conn);
-    pn->send_msg(ping, this);
+    pn->send_msg(MsgPing(pn->listen_port), this);
 }
 
-template<typename MsgType>
-void PeerNetwork<MsgType>::Peer::ping_timer(evutil_socket_t, short) {
+template<typename O, O _, O __>
+void PeerNetwork<O, _, __>::Peer::ping_timer(evutil_socket_t, short) {
     ping_timer_ok = true;
     if (pong_msg_ok)
     {
@@ -578,13 +636,13 @@ void PeerNetwork<MsgType>::Peer::ping_timer(evutil_socket_t, short) {
     }
 }
 
-template<typename MsgType>
-const std::vector<NetAddr> &PeerNetwork<MsgType>::all_peers() const {
+template<typename O, O _, O __>
+const std::vector<NetAddr> &PeerNetwork<O, _, __>::all_peers() const {
     return peer_list;
 }
 
-template<typename MsgType>
-void ClientNetwork<MsgType>::Conn::on_setup() {
+template<typename OpcodeType>
+void ClientNetwork<OpcodeType>::Conn::on_setup() {
     assert(this->get_mode() == Conn::PASSIVE);
     const auto &addr = this->get_addr();
     cn->addr2conn.erase(addr);
@@ -593,19 +651,26 @@ void ClientNetwork<MsgType>::Conn::on_setup() {
                         static_pointer_cast<Conn>(this->self())));
 }
 
-template<typename MsgType>
-void ClientNetwork<MsgType>::Conn::on_teardown() {
+template<typename OpcodeType>
+void ClientNetwork<OpcodeType>::Conn::on_teardown() {
     assert(this->get_mode() == Conn::PASSIVE);
     cn->addr2conn.erase(this->get_addr());
 }
 
+template<typename OpcodeType>
 template<typename MsgType>
-void ClientNetwork<MsgType>::send_msg(const MsgType &msg, const NetAddr &addr) {
+void ClientNetwork<OpcodeType>::send_msg(const MsgType &msg, const NetAddr &addr) {
     auto it = addr2conn.find(addr);
     if (it == addr2conn.end()) return;
     MsgNet::send_msg(msg, it->second);
 }
 
+template<typename O, O OPCODE_PING, O _>
+const O PeerNetwork<O, OPCODE_PING, _>::MsgPing::opcode = OPCODE_PING;
+
+template<typename O, O _, O OPCODE_PONG>
+const O PeerNetwork<O, _, OPCODE_PONG>::MsgPong::opcode = OPCODE_PONG;
+
 }
 
 #endif
diff --git a/include/salticidae/ref.h b/include/salticidae/ref.h
index 92d6b0d..f97bd43 100644
--- a/include/salticidae/ref.h
+++ b/include/salticidae/ref.h
@@ -59,8 +59,7 @@ template<typename T, typename D> class BoxObj;
 template<typename T, typename D>
 class _BoxObj {
     protected:
-    using ptr_type = T *;
-    ptr_type obj;
+    T *obj;
 
     template<typename T_, typename R, typename D_>
     friend class _RcObjBase;
@@ -68,9 +67,9 @@ class _BoxObj {
     friend class _BoxObj;
 
     public:
-
+    using type = T;
     constexpr _BoxObj(): obj(nullptr) {}
-    constexpr _BoxObj(ptr_type obj): obj(obj) {}
+    constexpr _BoxObj(T *obj): obj(obj) {}
     _BoxObj(const _BoxObj &other) = delete;
     _BoxObj(_BoxObj &&other): obj(other.obj) {
         other.obj = nullptr;
@@ -144,7 +143,7 @@ class BoxObj<T[], D>: public _BoxObj<T, D> {
 template<typename T, typename D = default_delete<T>, typename T_, typename D_>
 BoxObj<T, D> static_pointer_cast(BoxObj<T_, D_> &&other) {
     BoxObj<T, D> box{};
-    box.obj = static_cast<typename BoxObj<T, D>::ptr_type>(other.obj);
+    box.obj = static_cast<typename BoxObj<T, D>::type *>(other.obj);
     return std::move(box);
 }
 
@@ -280,8 +279,7 @@ class WeakObjBase<T[], R>: public _WeakObjBase<T, R> {
 template<typename T, typename R, typename D>
 class _RcObjBase {
     protected:
-    using ptr_type = T *;
-    ptr_type obj;
+    T *obj;
     R *ctl;
 
     friend _WeakObjBase<T, R>;
@@ -289,8 +287,9 @@ class _RcObjBase {
     friend class _RcObjBase;
 
     public:
+    using type = T;
     _RcObjBase(): obj(nullptr), ctl(nullptr) {}
-    _RcObjBase(ptr_type obj): obj(obj), ctl(new R()) {}
+    _RcObjBase(T *obj): obj(obj), ctl(new R()) {}
     _RcObjBase(BoxObj<T> &&box_ref): obj(box_ref.obj), ctl(new R()) {
         box_ref.obj = nullptr;
     }
@@ -438,7 +437,7 @@ template<typename T, typename D = default_delete<T>,
         typename T_, typename R_, typename D_>
 RcObjBase<T, R_, D> static_pointer_cast(const RcObjBase<T_, R_, D_> &other) {
     RcObjBase<T, R_, D> rc{};
-    rc.obj = static_cast<typename RcObjBase<T, R_, D>::ptr_type>(other.obj);
+    rc.obj = static_cast<typename RcObjBase<T, R_, D>::type *>(other.obj);
     if ((rc.ctl = other.ctl))
         rc.ctl->add_ref();
     return std::move(rc);
@@ -448,7 +447,7 @@ template<typename T, typename D = default_delete<T>,
         typename T_, typename R_, typename D_>
 RcObjBase<T, R_, D> static_pointer_cast(RcObjBase<T_, R_, D_> &&other) {
     RcObjBase<T, R_, D> rc{};
-    rc.obj = static_cast<typename RcObjBase<T, R_, D>::ptr_type>(other.obj);
+    rc.obj = static_cast<typename RcObjBase<T, R_, D>::type *>(other.obj);
     rc.ctl = other.ctl;
     other.ctl = nullptr;
     return std::move(rc);
-- 
cgit v1.2.3-70-g09d2