1 | #ifndef MXSTACK_INCLUDED // -*- C++ -*-
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2 | #define MXSTACK_INCLUDED
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3 | #if !defined(__GNUC__)
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4 | # pragma once
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5 | #endif
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6 |
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7 | /************************************************************************
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8 |
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9 | This provides a very simple typed-access stack class. It's really
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10 | just a convenience wrapper for the underlying MxDynBlock class.
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11 |
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12 | Copyright (C) 1998 Michael Garland. See "COPYING.txt" for details.
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13 |
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14 | $Id: MxStack.h,v 1.1 2002/09/24 16:53:54 wimmer Exp $
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15 |
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16 | ************************************************************************/
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17 |
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18 | #include "MxDynBlock.h"
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19 |
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20 | template<class T>
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21 | class MxStack : private MxDynBlock<T>
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22 | {
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23 | public:
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24 | MxStack(unsigned int n) : MxDynBlock<T>(n)
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25 | { }
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26 | MxStack(const T& val, unsigned int n) : MxDynBlock<T>(n)
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27 | { push(val); }
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28 |
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29 | T& top() { return last(); }
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30 | const T& top() const { return last(); }
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31 |
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32 | bool is_empty() { return length()==0; }
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33 |
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34 | T& pop() { return drop(); }
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35 |
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36 | void push(const T& val) { add(val); }
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37 | //
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38 | // NOTE: In this code, it is *crucial* that we do the add() and
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39 | // assignment in separate steps. The obvious alternative
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40 | // is something like { add(top()); }. But this is subtly
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41 | // broken! The top() will grab a pointer into the block,
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42 | // but the add() may reallocate the block before doing the
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43 | // assignment. Thus, the pointer will become invalid.
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44 | void push() { add(); top() = raw(length()-2); }
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45 | };
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46 |
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47 | // MXSTACK_INCLUDED
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48 | #endif
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