来自IntStack.cpp的容器和迭代器,作为一般的容器类使用模板来实现的
//: C16:StackTemplate.h
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Simple stack template
#ifndef STACKTEMPLATE_H
#define STACKTEMPLATE_H
#include "../require.h"
template<class T>
class StackTemplate {
enum { ssize = 100 };
T stack[ssize];
int top;
public:
StackTemplate() : top(0) {}
void push(const T& i) {
require(top < ssize, "Too many push()es");
stack[top++] = i;
}
T pop() {
require(top > 0, "Too many pop()s");
return stack[--top];
}
int size() { return top; }
};
#endif // STACKTEMPLATE_H ///:~
注意,模板会对它包含的对象做一定的假设
C++提供了一种弱类型机制,C++通常是强类型语言,弱类型不是坚持一个
类型是某个可接受的确切类型,而是只要求它想调用的成员函数对于一个特定
对象可用就行了
这里有一个用于检测模板的修正例子
//: C16:StackTemplateTest.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Test simple stack template
//{L} fibonacci
#include "fibonacci.h"
#include "StackTemplate.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
StackTemplate<int> is;
for(int i = 0; i < 20; i++)
is.push(fibonacci(i));
for(int k = 0; k < 20; k++)
cout << is.pop() << endl;
ifstream in("StackTemplateTest.cpp");
assure(in, "StackTemplateTest.cpp");
string line;
StackTemplate<string> strings;
while(getline(in, line))
strings.push(line);
while(strings.size() > 0)
cout << strings.pop() << endl;
getchar();
} ///:~
不同的是在实例is的创建中。在这个模板参数列表中,我们指明了栈和
迭代器应当存放的类型。
还需要的文件
//: C16:fibonacci.h
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Fibonacci number generator
int fibonacci(int n); ///:~
//: C16:fibonacci.cpp {O}
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
#include "../require.h"
int fibonacci(int n) {
const int sz = 100;
require(n < sz);
static int f[sz]; // Initialized to zero
f[0] = f[1] = 1;
// Scan for unfilled array elements:
int i;
for(i = 0; i < sz; i++)
if(f[i] == 0) break;
while(i <= n) {
f[i] = f[i-1] + f[i-2];
i++;
}
return f[n];
} ///:~
输出
6765
4181
2584
1597
987
610
377
233
144
89
55
34
21
13
8
5
3
2
1
1
} ///:~
getchar();
cout << strings.pop() << endl;
while(strings.size() > 0)
strings.push(line);
while(getline(in, line))
StackTemplate<string> strings;
string line;
assure(in, "StackTemplateTest.cpp");
ifstream in("StackTemplateTest.cpp");
cout << is.pop() << endl;
for(int k = 0; k < 20; k++)
is.push(fibonacci(i));
for(int i = 0; i < 20; i++)
StackTemplate<int> is;
int main() {
using namespace std;
#include <string>
#include <fstream>
#include <iostream>
#include "StackTemplate.h"
#include "fibonacci.h"
//{L} fibonacci
// Test simple stack template
// Copyright notice in Copyright.txt
// (c) Bruce Eckel 2000
// Available at http://www.BruceEckel.com
// From Thinking in C++, 2nd Edition
//: C16:StackTemplateTest.cpp