+// This may look like C code, but it is really -*- C++ -*-
+/*
+Copyright (C) 1988 Free Software Foundation
+ written by Doug Lea (dl@rocky.oswego.edu)
+
+This file is part of GNU CC.
+
+GNU CC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY. No author or distributor
+accepts responsibility to anyone for the consequences of using it
+or for whether it serves any particular purpose or works at all,
+unless he says so in writing. Refer to the GNU CC General Public
+License for full details.
+
+Everyone is granted permission to copy, modify and redistribute
+GNU CC, but only under the conditions described in the
+GNU CC General Public License. A copy of this license is
+supposed to have been given to you along with GNU CC so you
+can know your rights and responsibilities. It should be in a
+file named COPYING. Among other things, the copyright notice
+and this notice must be preserved on all copies.
+*/
+
+
+#ifndef _<T>PQ_h
+#ifdef __GNUG__
+#pragma once
+#pragma interface
+#endif
+#define _<T>PQ_h 1
+
+#include <Pix.h>
+#include "<T>.defs.h"
+
+class <T>PQ
+{
+protected:
+
+ int count;
+
+public:
+ int length(); // current number of items
+ int empty();
+
+ virtual Pix enq(<T&> item) = 0; // add item; return Pix
+ virtual <T> deq(); // return & remove min
+
+ virtual <T>& front() = 0; // access min item
+ virtual void del_front() = 0; // delete min item
+
+ virtual int contains(<T&> item); // is item in PQ?
+
+ virtual void clear(); // delete all items
+
+ virtual Pix first() = 0; // Pix of first item or 0
+ virtual void next(Pix& i) = 0; // advance to next or 0
+ virtual <T>& operator () (Pix i) = 0; // access item at i
+ virtual void del(Pix i) = 0; // delete item at i
+ virtual int owns(Pix i); // is i a valid Pix ?
+ virtual Pix seek(<T&> item); // Pix of item
+
+ void error(const char* msg);
+ virtual int OK() = 0; // rep invariant
+};
+
+#if defined(__OPTIMIZE__) || defined(USE_LIBGXX_INLINES)
+
+inline int <T>PQ::length()
+{
+ return count;
+}
+
+inline int <T>PQ::empty()
+{
+ return count == 0;
+}
+
+
+#endif
+#endif