[gstreamermm] Gst::Caps: fixed truncate method

[Marcin Kolny <mkolny src gnome org>]

commit b6fb4b9da227ad5d1a5e6a8b0e8690a85b5f4235
Author: Marcin Kolny <marcin kolny flytronic pl>
Date:   Thu Nov 27 13:34:32 2014 +0100

    Gst::Caps: fixed truncate method
    
        * gstreamer/src/caps.{ccg|hg}: truncate method takes as a first
          argument object instance which is transfer-full parameter. We need
          to do increase reference to avoid gobject errors.

 gstreamer/src/caps.ccg |    5 +++++
 gstreamer/src/caps.hg  |    9 ++++++++-
 2 files changed, 13 insertions(+), 1 deletions(-)
---
diff --git a/gstreamer/src/caps.ccg b/gstreamer/src/caps.ccg
index 9ba242c..7c65d95 100644
--- a/gstreamer/src/caps.ccg
+++ b/gstreamer/src/caps.ccg
@@ -156,5 +156,10 @@ void Caps::set_features(guint index, const CapsFeatures& features)
   gst_caps_set_features(gobj(), index, copy);
 }
 
+Glib::RefPtr<Gst::Caps> Caps::truncate()
+{
+  reference();
+  return Glib::wrap(gst_caps_truncate(gobj()));
+}
 
 } //namespace Gst
diff --git a/gstreamer/src/caps.hg b/gstreamer/src/caps.hg
index 5acdb5c..3a9a367 100644
--- a/gstreamer/src/caps.hg
+++ b/gstreamer/src/caps.hg
@@ -244,7 +244,14 @@ public:
    * @return A buffer (possibly the same pointer) that is writable.
    */
   Glib::RefPtr<Gst::Caps> create_writable();
-  _WRAP_METHOD(Glib::RefPtr<Gst::Caps> truncate(), gst_caps_truncate)
+
+  /** Discard all but the first structure from @a caps. Useful when
+   * fixating.
+   * 
+   * @return Truncated caps.
+   */
+  Glib::RefPtr<Gst::Caps> truncate();
+  _IGNORE(gst_caps_truncate)
 
   /**
    * Finds the features in caps that has the index index , and returns it.