fixes #381 Want comparators for various types

1 files changed, 50 insertions, 0 deletions

diff --git a/docs/man/nng_socket_id.3.adoc b/docs/man/nng_socket_id.3.adoc
new file mode 100644
index 00000000..b5acc98b
--- /dev/null
+++ b/docs/man/nng_socket_id.3.adoc
@@ -0,0 +1,50 @@
+= nng_socket_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_socket_id - return numeric socket identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_socket_id(nng_socket s);
+----
+
+== DESCRIPTION
+
+The `nng_socket_id()` function returns a positive identifier for the socket _s_,
+if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A socket is considered valid if it was ever opened with a protocol
+constructor, such as the <<nng_req0_open.3#,`nng_req0_open`>> function.
+Sockets that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_socket.5#NNG_SOCKET_INITIALIZER,`NNG_SOCKET_INITIALIZER`>> to ensure that
+they cannot be confused with a valid socket before they are opened.
+
+== RETURN VALUES
+
+This function returns the positive value for the socket identifier, or
+`-1` if the socket is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_socket.5#,nng_socket(5)>>,
+<<nng.7#,nng(7)>>