C++可变长参数模版(Variadic Templates)

/*  * File:   main.cpp * Author: Vicky.H * Email:  [e-mail] */#include <iostream>template<int Index, typename... Elements>struct Tuple_Impl;template<int Index>struct Tuple_Impl<Index> {};template<int Index, typename Head, typename... Tail>struct Tuple_Impl<Index, Head, Tail...> : public Tuple_Impl<Index + 1, Tail...> {};// extend template templatetemplate<typename T>struct eval {};// specializationtemplate<    template<typename, typename...> class TT,    typename T1,    typename... Rest>struct eval<TT<T1, Rest... >>{    void operator=(int) {    };};template<typename T1> struct A;template<typename T1, typename T2> struct B;template<int N> struct C;template<typename T1, int N> struct D;template<typename T1, typename T2, int N = 17 > struct E;/* * 警告：variadic templates 只在 -std=c++0x 或 -std=gnu++0x 下可用 */int main(void) {    eval < A<int >> ea;    eval < B<int, float >> eb;    eval < C < 17 >> ec;    eval < D<int, 17 >> ed;    eval < E<int, float >> ee;    return 0;}

/*  * File:   main.cpp * Author: Vicky.H * Email:  [e-mail] */#include <iostream>/**获得可变参数长度*/template<typename ... Args>std::size_t sizeof_args(Args ... args){    return sizeof...(args);}template<typename T>inline T add() {    std::cout << "DONE2" << std::endl;    return 0;}template<typename T, typename... Args >inline T add(T && t, Args && ... args) {    std::cout << "sizeof_args(args...) : " << sizeof_args(args...) << std::endl;    return t + add<T> (args...);}/* *  */int main(void) {    std::cout << add(1.0,2.0,3.0,4.0,5.0) << std::endl;    std::cout << "---------------------------" << std::endl;    std::cout << add(10,20,30,40,50,60,70,80,90) << std::endl;        return 0;}

/*  * File:   main.cpp * Author: Vicky.H * Email:  [e-mail] */#include <iostream>int add(int i, int j) {    return i + j;}int doadd(int (*f)(int, int), int i, int j) {    f(i, j);}template <typename T>T plus() {    return 0;}//----template <typename T>void func01(T& o1, T& o2) {    std::cout << "func01 begin o1 = " << o1 << " o2 = " << o2 << std::endl;    o1 += o2;    std::cout << "func01 end   o1 = " << o1 << " o2 = " << o2 << std::endl;}template <typename T>void func02(T& o1, T& o2) {    std::cout << "func02 begin o1 = " << o1 << " o2 = " << o2 << std::endl;    o1 -= o2;    std::cout << "func02 end   o1 = " << o1 << " o2 = " << o2 << std::endl;}template <typename T>void dofunc(void (*func01)(T&, T&), void (*func02)(T&, T&), T& o1, T& o2) {    func01(o1, o2);    func02(o1, o2);}//----template <typename T>void dofunclist() {}template <typename T,typename ...F>void dofunclist(F(* ...funcs)(T&,T&)) {}/* *  */int main(void) {    std::cout << "dofunc(&add,10,20) = " << doadd(&add, 10, 20) << std::endl;    std::cout << "---------------------------" << std::endl;    int i = 10;    int j = 10;    dofunc(func01, func02, i, j);    return 0;}

/*  * File:   main.cpp * Author: Vicky.H * Email:  [e-mail] */#include <iostream>#include <string.h>class GameObj {public:    virtual void attack() = 0;    virtual ~GameObj() { }};class Player : public GameObj {public:    Player(const char* _name) {        strcpy(name, _name);    }    void attack() {        std::cout << "PLAYER[" << name << "] attack" << std::endl;    }private:    char name[10];};class Monster : public GameObj {public:    Monster(const char* _name) {        strcpy(name, _name);    }    void attack() {        std::cout << "MONSTER[" << name << "] attack" << std::endl;    }private:    char name[10];};inline void attack() {    std::cout << "OVER" << std::endl;}template <typename T, typename ... Args>inline void attack(T&& o, Args&& ... args) {    static int i = 0;    std::cout << &i /**i的地址不同!*/ << "\t" << i++ << "\t";    o.attack();    attack(args...);}inline void attack2() {    static int i = 0;    std::cout << i++ << std::endl;}/* *  */int main(void) {    Player p1("p1");    Player p2("p2");    Player p3("p3");    Player p4("p4");    Player p5("p5");    Monster m1("m1");    Monster m2("m2");    Monster m3("m3");    attack(p1, m1, p2, m2, p3, m3, p4, p5);            std::cout << "---------------------------" << std::endl;        for (int i = 0; i < 10; i++) {        attack2(); // 注意!!!!    }    return 0;}