c++ 11 tuple实现

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variadic_templates.h

#ifndef __VARIADIC_TEMPLATES__H__#define __VARIADIC_TEMPLATES__H__#include <iostream>using namespace std;namespace anl{    // =============== tuple 存储不同类型的数据 ======================//    template<typename... TList> class tuple;    template<> class tuple<>{};    template<typename T, typename... TList>    class tuple<T, TList...>        : private tuple<TList...>    {    public:        typedef T value_type;        typedef tuple<TList...> base_type;        typedef tuple<T, TList...> this_type;    public:        tuple(const T& v, const TList&... tails)            : base_type(tails...)            , _value(v)        {            cout << "tuple(const T& v, const TList&... tails) " << v << endl;        }        tuple(const T&& v, const TList&&... tails)            : base_type(std::forward<const TList>(tails)...)            , _value(v)        {            cout << "tuple(const T&& v, const TList&&... tails) " << v << endl;        }        /*        // 本来是想使用下面的两个构造函数, 但是测试的时候发现有bug        // 在递归构造的时候, 第一次触发构造方式第一参数是右值以后, 后面的都会进入第一参数是右值的构造        // 最后只能要不全是右值的, 要不就全不是右值 来处理        tuple(const T& v, const TList&... tails)            : base_type(std::forward<const TList>(tails)...)            , _value(v)        {            cout << "tuple(const T& v, const TList&... tails) " << v << endl;        }        tuple(const T&& v, const TList&... tails)            : base_type(std::forward<const TList>(tails)...)            , _value(v)        {            cout << "tuple(const T&& v, const TList&... tails) " << v << endl;        }        */        tuple(const this_type& other)            :base_type(static_cast<const base_type&>(other))            , _value(other._value)        {            cout << "tuple(const this_type& other) " << other._value << endl;        }        tuple(const this_type&& other)            :base_type(static_cast<const base_type&&>(other))            , _value(other._value)        {            std::cout << "tuple(const this_type&& other) " << other._value << endl;        }        const T& head() const { return _value; }        T& head() { return this->_value; }        this_type& operator = (const this_type& other)        {            cout << "this_type& operator = (const this_type& other) " << other._value << endl;            base_type::operator = (static_cast<const base_type&>(other));            _value = other._value;            return *this;        }        this_type& operator = (this_type&& other)        {            cout << "this_type& operator = (this_type&& other) " << other._value << endl;            base_type::operator = (std::move(static_cast<base_type>(other)));            _value = other._value;            return *this;        }    protected:        T _value;    };    // =============== 获取第N个数据的类型 ======================//    template<unsigned int N, typename... TList> struct tuple_at;    template<unsigned int N, typename T, typename... TList>    struct tuple_at< N, tuple<T, TList...> >    {        typedef typename tuple_at< N - 1, tuple<TList...> >::value_type value_type;        typedef typename tuple_at< N - 1, tuple<TList...> >::tuple_type tuple_type;    };    template<typename T, typename... TList>    struct tuple_at< 0, tuple<T, TList...> >    {        typedef typename T value_type;        typedef typename tuple<T, TList...> tuple_type;    };    // =============== tuple_get: 取出第N个数据 ======================//    template<unsigned int N, typename... TList>    const typename tuple_at<N, tuple<TList...> >::value_type&        tuple_get(const tuple<TList...>& tp)    {        typedef tuple<TList...> tuple_type;        typedef typename tuple_at<N, tuple_type>::tuple_type base_tuple_type;        return static_cast<const base_tuple_type&>(tp).head();    }    template<unsigned int N, typename... TList>    typename tuple_at<N, tuple<TList...> >::value_type&        tuple_get(tuple<TList...>& tuple_)    {        typedef tuple<TList...> tuple_type;        typedef typename tuple_at<N, tuple_type >::tuple_type base_tuple_type;        return static_cast<base_tuple_type&>(tuple_).head();    }    // =============== makeTuple: 创建tuple ======================//    template<typename... Type>    tuple<Type...> makeTuple(const Type&... args)    {        std::cout << "tuple<Type...> makeTuple(const Type&... args) " << endl;        return tuple<Type...>(args...);    }    template<typename... Type>    tuple<Type...> makeTuple(const Type&&... args)    {        std::cout << "tuple<Type...> makeTuple(const Type&&... args)" << endl;        return tuple<Type...>(std::forward<const Type>(args)...);    }}#endif

main.cpp

#include <iostream>#include "Classes/variadic_templates.h"int main(){    int v[] = { 1, 2, 3};    cout << "===== 1" << endl;    auto tp1 = anl::tuple<int, int, int>(1, 2, 3);    cout << "===== 2" << endl;    auto tp2 = anl::tuple<int, int, int>(1, v[1], 3);    cout << "===== 3" << endl;    auto tp3 = anl::tuple<int, int, int>(v[0], 2, v[2]);    cout << "===== 4" << endl;    auto tp4 = anl::tuple<int, int, int>(v[0], v[1], v[2]);    cout << "===== 5" << endl;    auto tp5 = tp1;    cout << "===== 6" << endl;    auto tp6(tp2);    cout << "===== 7" << endl;    auto tp7 = std::move(tp3);    cout << "===== 8" << endl;    auto tp8(std::move(tp4));    cout << "===== 9" << endl;    auto tp11 = anl::makeTuple(1, 2, 3);    cout << "===== 10" << endl;    auto tp12 = anl::makeTuple(1, v[1], 3);    cout << "===== 11" << endl;    auto tp13 = anl::makeTuple(v[0], 2, v[2]);    cout << "===== 12" << endl;    auto tp14 = anl::makeTuple(v[0], v[1], v[2]);    cout << "===== 13" << endl;    return 0;}

感谢饭后温柔 http://www.cnblogs.com/flytrace/p/3574647.html
在他的基础上做了一些修改
1. 添加了makeTuple方法
2. 删掉了一些自己觉得没用的代码
3. 改了一些右值可能产生的bug
4. 添加了打印

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