stack.h

来自「This is the second part of that lab manu」· C头文件 代码 · 共 84 行

//: C02:Stack.h
// From "Thinking in C++, 2nd Edition, Volume 2"
// by Bruce Eckel & Chuck Allison, (c) 2001 MindView, Inc.
// Available at www.BruceEckel.com.
#include <cassert>
#include <cstddef>
#include <stdexcept>
#include <string>
#include <new>

using std::logic_error;
using std::string;
using std::bad_alloc;

// MS std namespace work-around
#ifndef _MSC_VER
using std::size_t;
#endif

class StackError : public logic_error {
public:
  StackError(const string& s) : logic_error(s) {}
};

template<typename T>
class Stack {
public:
  Stack(size_t) throw(StackError, bad_alloc);
  ~Stack();
  void push(const T&) throw(StackError);
  T pop() throw(StackError);
  T top() const throw(StackError);
  size_t size() const;
private:
  T* data;
  size_t max;
  size_t ptr;
};

template<typename T>
inline Stack<T>::~Stack() {
  delete [] data;
  max = ptr = 0;
}

template<typename T>
inline size_t Stack<T>::size() const {
  return ptr;
}

template<typename T>
Stack<T>::Stack(size_t siz) 
  throw(StackError, bad_alloc) {
  if (siz == 0)
    throw StackError("bad size in Stack(size_t)");
  data = new T[siz];
  max = siz;
  ptr = 0;
}

template<typename T>
void Stack<T>::push(const T& x) 
  throw(StackError) {
  if (ptr == max)
    throw StackError("stack overflow");

  assert(ptr < max);
  data[ptr++] = x;
}

template<typename T>
T Stack<T>::pop() throw(StackError) {
  if (ptr == 0)
    throw StackError("stack underflow");
  return data[--ptr];
}

template<typename T>
T Stack<T>::top() const throw(StackError) {
  if (ptr == 0)
    throw StackError("stack underflow");
  return data[ptr - 1];
} ///:~