new file

git-svn-id: svn://localhost/ardour2/branches/3.0@6686 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/pbd/property.cc

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+/*
+    Copyright (C) 2010 Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "pbd/properties.h"
+#include "pbd/error.h"
+
+#include "i18n.h"
+
+using namespace PBD;
+
+PropertyChange
+new_change ()
+{
+	static uint64_t change_bit = 1;
+
+	/* catch out-of-range */
+	if (!change_bit) {
+		fatal << _("programming error: ")
+			<< "change_bit out of range in ARDOUR::new_change()"
+			<< endmsg;
+		/*NOTREACHED*/
+	}
+
+	PropertyChange c = PropertyChange (change_bit);
+	change_bit <<= 1;	// if it shifts too far, change_bit == 0
+
+	return c;
+}
+