fixes #375 integer types are error prone

This change converts the various integer types like nng_socket
in the public API to opaque structures that are passed by value.
Basically we just wrap the integer ID.  This "hack" give us strong
type checks by the compiler (yay!), at the expense of not being able
to directly use these as numbers (so comparisions for example don't
work, and neither does initialization to zero using the normal
method.

Comparison of disassembly output shows that at least with the optimizer
enabled there is no difference in the compiler output between using
a structure or an integral value.

1 files changed, 22 insertions, 21 deletions

diff --git a/tests/trantest.h b/tests/trantest.h
index cbed58f3..ed1eccb7 100644
--- a/tests/trantest.h
+++ b/tests/trantest.h
@@ -172,7 +172,7 @@ trantest_dial(trantest *tt, nng_dialer *dp)
 {
 	nng_dialer d;
 	int        rv;
-	*dp = 0;
+	d.id = 0;
 
 	rv = nng_dialer_create(&d, tt->reqsock, tt->addr);
 	if (rv != 0) {
@@ -197,7 +197,7 @@ trantest_listen(trantest *tt, nng_listener *lp)
 {
 	int          rv;
 	nng_listener l;
-	*lp = 0;
+	l.id = 0;
 
 	rv = nng_listener_create(&l, tt->repsock, tt->addr);
 	if (rv != 0) {
@@ -231,12 +231,13 @@ void
 trantest_conn_refused(trantest *tt)
 {
 	Convey("Connection refused works", {
-		nng_dialer d = 0;
+		nng_dialer d;
+		d.id = 0;
 
 		So(trantest_dial(tt, &d) == NNG_ECONNREFUSED);
-		So(d == 0);
+		So(d.id == 0);
 		So(trantest_dial(tt, &d) == NNG_ECONNREFUSED);
-		So(d == 0);
+		So(d.id == 0);
 	});
 }
 
@@ -248,10 +249,10 @@ trantest_duplicate_listen(trantest *tt)
 		int          rv;
 		rv = trantest_listen(tt, &l);
 		So(rv == 0);
-		So(l != 0);
-		l = 0;
+		So(l.id != 0);
+		l.id = 0;
 		So(trantest_listen(tt, &l) == NNG_EADDRINUSE);
-		So(l == 0);
+		So(l.id == 0);
 	});
 }
 
@@ -262,12 +263,12 @@ trantest_listen_accept(trantest *tt)
 		nng_listener l;
 		nng_dialer   d;
 		So(trantest_listen(tt, &l) == 0);
-		So(l != 0);
+		So(l.id != 0);
 
 		nng_msleep(200);
-		d = 0;
+		d.id = 0;
 		So(trantest_dial(tt, &d) == 0);
-		So(d != 0);
+		So(d.id != 0);
 	});
 }
 
@@ -284,9 +285,9 @@ trantest_send_recv(trantest *tt)
 		char *       url;
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l != 0);
+		So(l.id != 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d != 0);
+		So(d.id != 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -312,7 +313,7 @@ trantest_send_recv(trantest *tt)
 		So(nng_msg_len(recv) == strlen("acknowledge"));
 		So(strcmp(nng_msg_body(recv), "acknowledge") == 0);
 		p = nng_msg_get_pipe(recv);
-		So(p != 0);
+		So(p.id != 0);
 		So(nng_pipe_getopt_string(p, NNG_OPT_URL, &url) == 0);
 		So(strcmp(url, tt->addr) == 0);
 		nng_strfree(url);
@@ -334,9 +335,9 @@ trantest_send_recv_multi(trantest *tt)
 		char         msgbuf[16];
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l != 0);
+		So(l.id != 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d != 0);
+		So(d.id != 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -366,7 +367,7 @@ trantest_send_recv_multi(trantest *tt)
 			So(nng_msg_len(recv) == strlen(msgbuf) + 1);
 			So(strcmp(nng_msg_body(recv), msgbuf) == 0);
 			p = nng_msg_get_pipe(recv);
-			So(p != 0);
+			So(p.id != 0);
 			So(nng_pipe_getopt_string(p, NNG_OPT_URL, &url) == 0);
 			So(strcmp(url, tt->addr) == 0);
 			nng_strfree(url);
@@ -386,9 +387,9 @@ trantest_check_properties(trantest *tt, trantest_proptest_t f)
 		int          rv;
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l != 0);
+		So(l.id != 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d != 0);
+		So(d.id != 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -429,9 +430,9 @@ trantest_send_recv_large(trantest *tt)
 		}
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l != 0);
+		So(l.id != 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d != 0);
+		So(d.id != 0);
 
 		nng_msleep(200); // listener may be behind slightly