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diff --git a/src/base/PropertyName.h b/src/base/PropertyName.h
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+// -*- c-basic-offset: 4 -*-
+
+
+/*
+    Rosegarden
+    A sequencer and musical notation editor.
+
+    This program is Copyright 2000-2008
+        Guillaume Laurent   <[email protected]>,
+        Chris Cannam        <[email protected]>,
+        Richard Bown        <[email protected]>
+
+    The moral right of the authors to claim authorship of this work
+    has been asserted.
+
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef _PROPERTY_NAME_H_
+#define _PROPERTY_NAME_H_
+
+#include <string>
+#include <map>
+#include <iostream>
+
+namespace Rosegarden 
+{
+
+/**
+
+  A PropertyName is something that can be constructed from a string,
+  compared quickly as an int, hashed as a key in a hash map, and
+  streamed out again as a string.  It must have accompanying functors
+  PropertyNamesEqual and PropertyNameHash which compare and hash
+  PropertyName objects.
+
+  The simplest implementation is a string:
+
+    typedef std::string PropertyName;
+
+    struct PropertyNamesEqual {
+      bool operator() (const PropertyName &s1, const PropertyName &s2) const {
+        return s1 == s2;
+      }
+    };
+
+    struct PropertyNameHash {
+      static std::hash<const char *> _H;
+      size_t operator() (const PropertyName &s) const {
+          return _H(s.c_str());
+      }
+    };
+
+    std::hash<const char *> PropertyNameHash::_H;
+
+  but our implementation is faster in practice: while it behaves
+  outwardly like a string, for the Event that makes use of it,
+  it performs much like a machine integer.  It also shares
+  strings, reducing storage sizes if there are many names in use.
+
+  A big caveat with this class is that it is _not_ safe to persist
+  the values of PropertyNames and assume that the original strings
+  can be recovered; they can't.  The values are assigned on demand,
+  and there's no guarantee that a given string will always map to
+  the same value (on separate invocations of the program).  This
+  is why there's no PropertyName(int) constructor and no mechanism
+  for storing PropertyNames in properties.  (Of course, you can 
+  store the string representation of a PropertyName in a property;
+  but that's slow.)
+
+*/
+
+class PropertyName
+{
+public:
+    PropertyName() : m_value(-1) { }
+    PropertyName(const char *cs) { std::string s(cs); m_value = intern(s); }
+    PropertyName(const std::string &s) : m_value(intern(s)) { }
+    PropertyName(const PropertyName &p) : m_value(p.m_value) { }
+    ~PropertyName() { }
+
+    PropertyName &operator=(const char *cs) {
+        std::string s(cs);
+        m_value = intern(s);
+        return *this;
+    }
+    PropertyName &operator=(const std::string &s) {
+        m_value = intern(s);
+        return *this;
+    }
+    PropertyName &operator=(const PropertyName &p) {
+        m_value = p.m_value;
+        return *this;
+    }
+
+    bool operator==(const PropertyName &p) const {
+        return m_value == p.m_value;
+    }
+    bool operator< (const PropertyName &p) const {
+        return m_value <  p.m_value;
+    }
+
+    const char *c_str() const {
+        return getName().c_str();
+    }
+
+    std::string getName() const /* throw (CorruptedValue) */;
+
+    int getValue() const { return m_value; }
+
+    static const PropertyName EmptyPropertyName;
+    
+private:
+    typedef std::map<std::string, int> intern_map;
+    typedef intern_map::value_type intern_pair;
+
+    typedef std::map<int, std::string> intern_reverse_map;
+    typedef intern_reverse_map::value_type intern_reverse_pair;
+
+    static intern_map *m_interns;
+    static intern_reverse_map *m_internsReversed;
+    static int m_nextValue;
+
+    int m_value;
+
+    static int intern(const std::string &s);
+};
+
+inline std::ostream& operator<<(std::ostream &out, const PropertyName &n) {
+    out << n.getName();
+    return out;
+}
+
+inline std::string operator+(const std::string &s, const PropertyName &n) {
+    return s + n.getName();
+}
+
+struct PropertyNamesEqual
+{
+    bool operator() (const PropertyName &s1, const PropertyName &s2) const {
+        return s1 == s2;
+    }
+};
+
+struct PropertyNameHash
+{
+    size_t operator() (const PropertyName &s) const {
+        return static_cast<size_t>(s.getValue());
+    }
+};
+
+}
+
+#endif