C++ Templates笔记 5 类模板的特化

#include <deque>#include <string>#include <stdexcept>//#include "stack1.hpp"#include <iostream>#include <string>#include <cstdlib>#include <vector>template <typename T>class Stack { private: std::vector < T > elems; // elements public: void push(T const&); // push element void pop(); // pop element T top() const; // return top element bool empty() const { // return whether the stack is empty return elems.empty(); }};template <typename T>void Stack<T>::push (T const& elem){ elems.push_back(elem); // append copy of passed elem}template<typename T>void Stack<T>::pop (){ if (elems.empty()) { throw std::out_of_range("Stack<>::pop(): empty stack"); } elems.pop_back(); // remove last element}template <typename T>T Stack<T>::top () const{ if (elems.empty()) { throw std::out_of_range("Stack<>::top(): empty stack"); } return elems.back(); // return copy of last element}template<>class Stack<std::string> {private:std::deque<std::string> elems; // elementspublic:void push(std::string const&); // push elementvoid pop(); // pop elementstd::string top() const; // return top elementbool empty() const { // return whether the stack is emptyreturn elems.empty();}};void Stack<std::string>::push (std::string const& elem){elems.push_back(elem); // append copy of passed elem}void Stack<std::string>::pop (){if (elems.empty()) {throw std::out_of_range("Stack<std::string>::pop(): empty stack");}elems.pop_back(); // remove last element}std::string Stack<std::string>::top () const{if (elems.empty()) {throw std::out_of_range("Stack<std::string>::top(): empty stack");}return elems.back(); // return copy of last element}int main(){ try { Stack<int> intStack; // stack of ints Stack<std::string> stringStack; // stack of strings // manipulate int stack intStack.push(7); std::cout << intStack.top() << std::endl; intStack.pop(); // manipulate string stack stringStack.push("hello"); std::cout << stringStack.top() << std::endl; stringStack.pop(); stringStack.pop(); } catch (std::exception const& ex) { std::cerr << "Exception: " << ex.what() << std::endl; return EXIT_FAILURE; // exit program with ERROR status }}/*类模板的特化，通过特化类模板，可以优化给予某种特定类型的实现，或者克服某种特定类型在实例化类模板是出现的不足。如果要特化一个类模板，就要特化该类模板的所有成员函数。7helloException: Stack<std::string>::pop(): empty stack从上面代码的执行效果可以看出它调用执行了函数类模板的特化*/