Problem: proxy is not typesafe

tests/socket.cpp

@@ -1,5 +1,8 @@
 #include <catch.hpp>
 #include <zmq.hpp>
+#ifdef ZMQ_CPP11
+#include <future>
+#endif
 
 TEST_CASE("socket create destroy", "[socket]")
 {
@@ -27,3 +30,59 @@ TEST_CASE("socket sends and receives const buffer", "[socket]")
     CHECK(2 == receiver.recv(buf, 2));
     CHECK(0 == memcmp(buf, "Hi", 2));
 }
+
+#ifdef ZMQ_CPP11
+TEST_CASE("socket proxy", "[socket]")
+{
+    zmq::context_t context;
+    zmq::socket_t front(context, ZMQ_ROUTER);
+    zmq::socket_t back(context, ZMQ_ROUTER);
+    zmq::socket_t capture(context, ZMQ_DEALER);
+    front.bind("inproc://test1");
+    back.bind("inproc://test2");
+    capture.bind("inproc://test3");
+    auto f = std::async(std::launch::async, [&]() {
+        auto s1 = std::move(front);
+        auto s2 = std::move(back);
+        auto s3 = std::move(capture);
+        try
+        {
+            zmq::proxy(s1, s2, &s3);
+        }
+        catch (const zmq::error_t& e)
+        {
+            return e.num() == ETERM;
+        }
+        return false;
+    });
+    context.close();
+    CHECK(f.get());
+}
+
+TEST_CASE("socket proxy steerable", "[socket]")
+{
+    zmq::context_t context;
+    zmq::socket_t front(context, ZMQ_ROUTER);
+    zmq::socket_t back(context, ZMQ_ROUTER);
+    zmq::socket_t control(context, ZMQ_SUB);
+    front.bind("inproc://test1");
+    back.bind("inproc://test2");
+    control.connect("inproc://test3");
+    auto f = std::async(std::launch::async, [&]() {
+        auto s1 = std::move(front);
+        auto s2 = std::move(back);
+        auto s3 = std::move(control);
+        try
+        {
+            zmq::proxy_steerable(s1, s2, ZMQ_NULLPTR, &s3);
+        }
+        catch (const zmq::error_t& e)
+        {
+            return e.num() == ETERM;
+        }
+        return false;
+    });
+    context.close();
+    CHECK(f.get());
+}
+#endif

zmq.hpp

@@ -201,23 +201,6 @@ inline int poll(std::vector<zmq_pollitem_t> &items, long timeout_ = -1)
 #endif
 
 
-inline void proxy(void *frontend, void *backend, void *capture)
-{
-    int rc = zmq_proxy(frontend, backend, capture);
-    if (rc != 0)
-        throw error_t();
-}
-
-#ifdef ZMQ_HAS_PROXY_STEERABLE
-inline void
-proxy_steerable(void *frontend, void *backend, void *capture, void *control)
-{
-    int rc = zmq_proxy_steerable(frontend, backend, capture, control);
-    if (rc != 0)
-        throw error_t();
-}
-#endif
-
 inline void version(int *major_, int *minor_, int *patch_)
 {
     zmq_version(major_, minor_, patch_);
@@ -792,6 +775,45 @@ class socket_t
     void operator=(const socket_t &) ZMQ_DELETED_FUNCTION;
 };
 
+ZMQ_DEPRECATED("from 4.3.1, use proxy taking socket_t objects")
+inline void proxy(void *frontend, void *backend, void *capture)
+{
+    int rc = zmq_proxy(frontend, backend, capture);
+    if (rc != 0)
+        throw error_t();
+}
+
+inline void proxy(socket_t &frontend, socket_t &backend, socket_t *capture = ZMQ_NULLPTR)
+{
+    int rc = zmq_proxy(static_cast<void *>(frontend),
+                       static_cast<void *>(backend),
+                       capture ? static_cast<void *>(*capture) : ZMQ_NULLPTR);
+    if (rc != 0)
+       throw error_t();
+}
+
+#ifdef ZMQ_HAS_PROXY_STEERABLE
+ZMQ_DEPRECATED("from 4.3.1, use proxy_steerable taking socket_t objects")
+inline void
+proxy_steerable(void *frontend, void *backend, void *capture, void *control)
+{
+    int rc = zmq_proxy_steerable(frontend, backend, capture, control);
+    if (rc != 0)
+        throw error_t();
+}
+
+inline void
+proxy_steerable(socket_t &frontend, socket_t &backend, socket_t *capture, socket_t *control)
+{
+    int rc = zmq_proxy_steerable(static_cast<void *>(frontend),
+                                 static_cast<void *>(backend),
+                                 capture ? static_cast<void *>(*capture) : ZMQ_NULLPTR,
+                                 control ? static_cast<void *>(*control) : ZMQ_NULLPTR);
+    if (rc != 0)
+        throw error_t();
+}
+#endif
+
 class monitor_t
 {
   public: