.

wcfs/internal/_wcfs.pyx

@@ -59,8 +59,13 @@ cdef class PyWatchLink:
     cdef WatchLink *wlink
 
     def __xinit__(PyWatchLink pywlink, PyWCFS pywc):
-        _ = wcfs_openwatch_pyexc(pywc.wc)
-        # XXX
+        with nogil:
+            _ = wcfs_openwatch_pyexc(pywc.wc)
+            pywlink.wlink = _.first
+            err = _.second
+
+        if err != nil:
+            raise RuntimeError(err.Error())     # XXX exc class?
 
     def close(PyWatchLink pywlink):
         with nogil:

wcfs/internal/wcfs.h

@@ -28,6 +28,9 @@ using std::string;
 #include <tuple>
 using std::tuple;
 
+#include <utility>
+using std::pair;
+
 #include "wcfs_misc.h"
 
 struct Conn;
@@ -42,7 +45,7 @@ struct WCFS {
     tuple<Conn*, error>         connect(zodb::Tid at);
     string                      _path(const string &obj);
     tuple<os::File, error>      _open(const string &path, int flags=O_RDONLY);
-    tuple<WatchLink*, error>    _openwatch();
+    pair<WatchLink*, error>     _openwatch();
 };
 
 

wcfs/internal/wcfs_misc.h

@@ -38,6 +38,10 @@ using namespace golang;
 #include <string>
 using std::string;
 
+#include <utility>
+using std::pair;
+using std::make_pair;
+
 #include <tuple>
 using std::tuple;
 using std::make_tuple;

wcfs/internal/wcfs_watchlink.cpp

@@ -25,7 +25,7 @@
 
 
 // _openwatch opens new watch link on wcfs.
-tuple<WatchLink*, error> WCFS::_openwatch() {
+pair<WatchLink*, error> WCFS::_openwatch() {
     WCFS *wc = this;
 
     // head/watch handle.
@@ -33,7 +33,7 @@ tuple<WatchLink*, error> WCFS::_openwatch() {
     error err;
     tie(f, err) = wc->_open("head/watch", O_RDWR);
     if (err != nil)
-        return make_tuple((WatchLink *)NULL, err);
+        return make_pair((WatchLink *)NULL, err);
 
     WatchLink *wlink = new(WatchLink);
     wlink->_wc        = wc;
@@ -49,7 +49,7 @@ tuple<WatchLink*, error> WCFS::_openwatch() {
     wlink->_serveWG.go(wlink._serveRX)
 #endif
 
-    return make_tuple(wlink, nil);
+    return make_pair(wlink, nil);
 }
 
 void WatchLink::_closeTX() {

wcfs/internal/wcfs_watchlink.h

@@ -85,7 +85,7 @@ class WatchLink {
 #endif
 
 public:
-    friend tuple<WatchLink*, error> WCFS::_openwatch();
+    friend pair<WatchLink*, error> WCFS::_openwatch();
     error close();
     error recvReq(context::Context *ctx, PinReq *rx_into);
     tuple<string, error> sendReq(context::Context *ctx, const string &req);