C++ Templates筆記 4 類模板Stack

#include <vector><br />#include <stdexcept><br />#include <iostream><br />#include <string><br />#include <cstdlib></p><p>template <typename T><br />class Stack {<br />private:<br />std::vector<T> elems; // elements</p><p>public:<br />void push(T const&); // push element<br />void pop(); // pop element<br />T top() const; // return top element<br />bool empty() const { // return whether the stack is empty<br />return elems.empty();<br />}<br />};</p><p>template <typename T><br />void Stack<T>::push (T const& elem)<br />{<br />elems.push_back(elem); // append copy of passed elem<br />}</p><p>template<typename T><br />void Stack<T>::pop ()<br />{<br />if (elems.empty()) {<br />throw std::out_of_range("Stack<>::pop(): empty stack");<br />}<br />elems.pop_back(); // remove last element<br />}</p><p>template <typename T><br />T Stack<T>::top () const<br />{<br />if (elems.empty()) {<br />throw std::out_of_range("Stack<>::top(): empty stack");<br />}<br />return elems.back(); // return copy of last element<br />}<br />int main()<br />{<br />try {<br />Stack<int> intStack; // stack of ints<br />Stack<std::string> stringStack; // stack of strings</p><p>// manipulate int stack<br />intStack.push(7);<br />std::cout << intStack.top() << std::endl;</p><p>// manipulate string stack<br />stringStack.push("hello");<br />std::cout << stringStack.top() << std::endl;<br />stringStack.pop();<br />stringStack.pop();<br />}<br />catch (std::exception const& ex) {<br />std::cerr << "Exception: " << ex.what() << std::endl;<br />return EXIT_FAILURE; // exit program with ERROR status<br />}<br />}<br />