new config manager. not everything is completed, and some things will still be changed, but it seems to work well enough to put it into CVS

svn-id: r10687

1 files changed, 57 insertions, 0 deletions

diff --git a/common/singleton.h b/common/singleton.h
new file mode 100644
index 0000000000..be40b45f42
--- /dev/null
+++ b/common/singleton.h
@@ -0,0 +1,57 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2001  Ludvig Strigeus
+ * Copyright (C) 2001-2003 The ScummVM project
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#ifndef COMMON_SINGLETON_H
+#define COMMON_SINGLETON_H
+
+namespace Common {
+
+/**
+ * Generic template base class for implementing the singleton design pattern.
+ */
+template <class T>
+class Singleton
+{
+public:
+	static T& instance() {
+		// TODO: We aren't thread safe. For now we ignore it since the
+		// only thing using this singleton template is the config manager,
+		// and that is first instantiated long before any threads.
+		// TODO: We don't leak, but the destruction order is nevertheless
+		// semi-random. If we use multiple singletons, the destruction
+		// order might become an issue. There are various approaches
+		// to solve that problem, but for now this is sufficient
+		static T singleton;
+		return singleton;
+	}
+protected:
+	Singleton<T>()		{ }
+	~Singleton<T>()		{ }
+
+private:
+	Singleton(const Singleton&);
+	Singleton& operator= (const Singleton&);
+}; 
+
+}	// End of namespace Common
+
+#endif