1 files changed, 187 insertions, 0 deletions
diff --git a/gnu/lib/libg++/g++-include/SkipSet.hP b/gnu/lib/libg++/g++-include/SkipSet.hP
new file mode 100644
index 000000000000..cd953052394d
--- /dev/null
+++ b/gnu/lib/libg++/g++-include/SkipSet.hP
@@ -0,0 +1,187 @@
+// This may look like C code, but it is really -*- C++ -*-
+/* 
+Copyright (C) 1991 Free Software Foundation
+
+This file is part of the GNU C++ Library.  This library is free
+software; you can redistribute it and/or modify it under the terms of
+the GNU Library General Public License as published by the Free
+Software Foundation; either version 2 of the License, or (at your
+option) any later version.  This library 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 Library General Public License for more details.
+You should have received a copy of the GNU Library General Public
+License along with this library; if not, write to the Free Software
+Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+ * Sets implemented via William Pugh SkipList algorithms.
+ * CACM, June 1990, p 668-676.
+ *
+ */
+
+#ifndef _<T>SkipSet_h
+#ifdef __GNUG__
+#pragma interface
+#endif
+#define _<T>SkipSet_h 1
+
+#include "<T>.Set.h"
+
+#include <values.h>
+#include <MLCG.h>
+
+class <T>SkipSet;
+class <T>RealSkipSetNode;
+
+class <T>SkipSetNode
+{
+friend class <T>SkipSet;
+  private:
+    <T>RealSkipSetNode * * forward;
+    <T>SkipSetNode(int size);
+};
+
+class <T>RealSkipSetNode : public <T>SkipSetNode
+{
+friend class <T>SkipSet;
+  private:
+    <T>             item;
+    <T>RealSkipSetNode(<T&> h, int size);
+};
+
+typedef <T>RealSkipSetNode* <T>SkipSetNodePtr;
+
+inline <T>SkipSetNode::<T>SkipSetNode(int size)
+: forward(new <T>SkipSetNodePtr[size+1])
+{
+}
+
+inline <T>RealSkipSetNode::<T>RealSkipSetNode(<T&> h, int size)
+: item(h),
+  <T>SkipSetNode(size)
+{
+}
+
+class <T>SkipSet : public <T>Set
+{
+friend class <T>SkipSetinit;
+  protected:
+    <T>SkipSetNode*   header;
+    int               level;
+    int               max_levels;
+    int               randoms_left;
+    long              random_bits;
+    
+    static MLCG*      gen;
+    int               random_level(void);
+    
+    <T>SkipSetNodePtr leftmost(void);
+    <T>SkipSetNodePtr rightmost(void);
+    <T>SkipSetNodePtr pred(<T>SkipSetNodePtr t);
+    <T>SkipSetNodePtr succ(<T>SkipSetNodePtr t);
+    void              _kill(void);
+    
+  private:
+    enum { BITS_IN_RANDOM = LONGBITS-1 };
+  public:
+    <T>SkipSet(long size=DEFAULT_INITIAL_CAPACITY);
+    <T>SkipSet(<T>SkipSet& a);
+    ~<T>SkipSet();
+    
+    Pix             add(<T&> i);
+    void            del(<T&> i);
+    int             contains(<T&> i);
+    
+    void            clear(void);
+    
+    Pix             first(void);
+    void            next(Pix& i);
+    <T>&            operator () (Pix i);
+    Pix             seek(<T&> i);
+    
+    Pix             last(void);
+    void            prev(Pix& i);
+    
+    void            operator |= (<T>SkipSet& b);
+    void            operator -= (<T>SkipSet& b);
+    void            operator &= (<T>SkipSet& b);
+    
+    int             operator == (<T>SkipSet& b);
+    int             operator != (<T>SkipSet& b);
+    int             operator <= (<T>SkipSet& b); 
+    
+    int             OK(void);
+};
+
+/*
+ *  A little overkill on the inlines.
+ *
+ */
+
+inline <T>SkipSet::~<T>SkipSet(void)
+{
+  _kill();
+  delete header;
+}
+
+inline int <T>SkipSet::operator != (<T>SkipSet& b)
+{
+  return ! (*this == b);
+}
+
+inline <T>SkipSetNodePtr <T>SkipSet::leftmost(void)
+{
+  return header->forward[0];
+}
+
+inline <T>SkipSetNodePtr <T>SkipSet::succ(<T>SkipSetNodePtr t)
+{
+  <T>SkipSetNodePtr result = 0;
+  if (t->forward[0]!=header) result = t->forward[0];
+  return result;
+}
+
+inline Pix <T>SkipSet::first(void)
+{
+  return Pix(leftmost());
+}
+
+inline Pix <T>SkipSet::last(void)
+{
+  return Pix(rightmost());
+}
+
+inline void <T>SkipSet::next(Pix& i)
+{
+  if (i != 0) i = Pix(succ((<T>SkipSetNodePtr)i));
+}
+
+inline void <T>SkipSet::prev(Pix& i)
+{
+  if (i != 0) i = Pix(pred((<T>SkipSetNodePtr)i));
+}
+
+inline <T>& <T>SkipSet::operator () (Pix i)
+{
+  if (i == 0) error("null Pix");
+  return ((<T>SkipSetNodePtr)i)->item;
+}
+
+
+inline int <T>SkipSet::contains(<T&> key)
+{
+  return seek(key) != 0;
+}
+
+static class <T>SkipSetinit
+{
+  public:
+    <T>SkipSetinit();
+    ~<T>SkipSetinit();
+  private:
+    static int count;
+} <T>skipSetinit;
+
+#endif