Make poller default movable

Latest modification to the poller made move constructor and move
assigment operator not complete. In order to prevent that in the future
poller should be default movable. Unique pointer has been used to
manager zmq_poller. That makes code simpler and safer now.

Author: kurdybacha

zmq.hpp

@@ -1018,36 +1018,19 @@ namespace zmq
     class poller_t
     {
     public:
-        poller_t () : poller_ptr (zmq_poller_new ())
+        poller_t ()
         {
             if (!poller_ptr)
                 throw error_t ();
         }
 
-        ~poller_t ()
-        {
-            if (poller_ptr)
-            {
-                int rc = zmq_poller_destroy (&poller_ptr);
-                assert(rc == 0);
-            }
-        }
+        ~poller_t () = default;
 
         poller_t(const poller_t&) = delete;
         poller_t &operator=(const poller_t&) = delete;
-        poller_t(poller_t&& src)
-          : poller_ptr(src.poller_ptr)
-          , poller_events(std::move (src.poller_events))
-        {
-            src.poller_ptr = NULL;
-        }
-        poller_t &operator=(poller_t&& src)
-        {
-            poller_ptr = src.poller_ptr;
-            poller_events = std::move (src.poller_events);
-            src.poller_ptr = NULL;
-            return *this;
-        }
+
+        poller_t(poller_t&& src) = default;
+        poller_t &operator=(poller_t&& src) = default;
 
         using handler_t = std::function<void(short)>;
 
@@ -1056,7 +1039,7 @@ namespace zmq
             auto it = std::end (handlers);
             auto inserted = false;
             std::tie(it, inserted) = handlers.emplace (socket.ptr, std::make_shared<handler_t> (std::move (handler)));
-            if (0 == zmq_poller_add (poller_ptr, socket.ptr, inserted && *(it->second) ? it->second.get() : nullptr, events)) {
+            if (0 == zmq_poller_add (poller_ptr.get (), socket.ptr, inserted && *(it->second) ? it->second.get() : nullptr, events)) {
                 need_rebuild = true;
                 return;
             }
@@ -1068,7 +1051,7 @@ namespace zmq
 
         void remove (zmq::socket_t &socket)
         {
-            if (0 == zmq_poller_remove (poller_ptr, socket.ptr)) {
+            if (0 == zmq_poller_remove (poller_ptr.get (), socket.ptr)) {
                 handlers.erase (socket.ptr);
                 need_rebuild = true;
                 return;
@@ -1078,7 +1061,7 @@ namespace zmq
 
         void modify (zmq::socket_t &socket, short events)
         {
-            if (0 != zmq_poller_modify (poller_ptr, socket.ptr, events))
+            if (0 != zmq_poller_modify (poller_ptr.get (), socket.ptr, events))
                 throw error_t ();
         }
 
@@ -1095,7 +1078,7 @@ namespace zmq
                 }
                 need_rebuild = false;
             }
-            int rc = zmq_poller_wait_all (poller_ptr, poller_events.data (),
+            int rc = zmq_poller_wait_all (poller_ptr.get (), poller_events.data (),
                                           static_cast<int> (poller_events.size ()),
                                           static_cast<long>(timeout.count ()));
             if (rc > 0) {
@@ -1117,7 +1100,14 @@ namespace zmq
         }
 
     private:
-        void *poller_ptr {nullptr};
+        std::unique_ptr<void, std::function<void(void*)>> poller_ptr
+        {
+            zmq_poller_new (),
+            [](void *ptr) {
+                int rc = zmq_poller_destroy (&ptr);
+                ZMQ_ASSERT (rc == 0);
+            }
+        };
         bool need_rebuild {false};
         std::unordered_map<void*, std::shared_ptr<handler_t>> handlers {};
         std::vector<zmq_poller_event_t> poller_events {};