Add socket_t::send_static (#678)

Author: cacharle

tests/socket.cpp

@@ -507,6 +507,47 @@ TEST_CASE("socket sends and receives const buffer", "[socket]")
     CHECK(0 == memcmp(buf, str, 2));
 }
 
+TEST_CASE("socket send_static", "[socket]")
+{
+    zmq::context_t context;
+    zmq::socket_t sender(context, ZMQ_PAIR);
+    zmq::socket_t receiver(context, ZMQ_PAIR);
+    receiver.bind("inproc://test");
+    sender.connect("inproc://test");
+    SECTION("send_static with const_buffer")
+    {
+        CHECK(6 == *sender.send_static(zmq::buffer("hello")));
+        char buf[6];
+        const auto res = receiver.recv(zmq::buffer(buf));
+        CHECK(res);
+        CHECK(!res->truncated());
+        CHECK(6 == res->size);
+        CHECK(0 == memcmp(buf, "hello", 6));
+    }
+#if CPPZMQ_HAS_STRING_VIEW
+    SECTION("send_static with std::string_view")
+    {
+        CHECK(5 == *sender.send_static(std::string_view{"hello"}));
+        char buf[5];
+        const auto res = receiver.recv(zmq::buffer(buf));
+        CHECK(res);
+        CHECK(!res->truncated());
+        CHECK(5 == res->size);
+        CHECK(0 == memcmp(buf, "hello", 5));
+    }
+    SECTION("send_static with char literal")
+    {
+        CHECK(5 == *sender.send_static("hello"));
+        char buf[5];
+        const auto res = receiver.recv(zmq::buffer(buf));
+        CHECK(res);
+        CHECK(!res->truncated());
+        CHECK(5 == res->size);
+        CHECK(0 == memcmp(buf, "hello", 5));
+    }
+#endif
+}
+
 #ifdef ZMQ_CPP11
 
 TEST_CASE("socket send none sndmore", "[socket]")

zmq.hpp

@@ -2029,6 +2029,25 @@ class socket_base
     }
 #endif
 
+    send_result_t send_static(const_buffer buf, send_flags flags = send_flags::none)
+    {
+        int nbytes =
+          zmq_send_const(_handle, buf.data(), buf.size(), static_cast<int>(flags));
+        if (nbytes >= 0)
+            return static_cast<size_t>(nbytes);
+        if (zmq_errno() == EAGAIN)
+            return {};
+        throw error_t();
+    }
+
+#if CPPZMQ_HAS_STRING_VIEW
+    send_result_t send_static(std::string_view str,
+                              send_flags flags = send_flags::none)
+    {
+        return send_static(zmq::buffer(str), flags);
+    }
+#endif
+
     ZMQ_CPP11_DEPRECATED(
       "from 4.3.1, use recv taking a mutable_buffer and recv_flags")
     size_t recv(void *buf_, size_t len_, int flags_ = 0)