如何打印tuple的元素及获取尾部元素组成的集合tuple

使用Ubuntu16.04 gcc -std11编译通过

#include 
#include 
#include 
#include 
using namespace std;

template
struct print_tuple {

    template<typename... T>
    static
    typename enable_if<(N < sizeof...(T))>::type
    print(ostream &os, const tuple &t) {
        os << ", " << get(t);
        print_tuple < N + 1 > ::print(os, t);
    }

    template<typename... T>
    static
    typename enable_ifsizeof...(T))>::type
    print(ostream &os, const tuple &) {
    }
} ;

ostream& operator<<(ostream& os, const tuple<>&) {
    os << "{}";
}

template<typename T0, typename... T>
ostream& operator<<(ostream& os, const tuple& t) {
    os << '{' << get<0>(t);
    print_tuple<1>::print(os, t);
    os << '}';
}

template
struct set_tuple {

    template<typename Head, typename... Tail>
    static
    typename enable_if<(N < sizeof...(Tail))>::type
    set(tuple &rt, const tuple &t) {
        get(rt) = get < N + 1 > (t);
        set_tuple < N + 1 > ::set(rt, t);
    }

    template<typename Head, typename... Tail>
    static
    typename enable_ifsizeof...(Tail))>::type
    set(tuple &, const tuple &) {
    }
} ;

tuple<> mytail(const tuple<> &t) {
    return tuple<>();
}

template<typename Head, typename... Tail>
tuple mytail(const tuple &t) {
    tuple rt;
    set_tuple<0>::set(rt, t);
    return rt;
}

int main(int argc, char** argv) {
    auto t1 = make_tuple(1, 1.2, "hello", -0x123456);

    cout << t1 << endl;
    cout << mytail(t1) << endl;
    return 0;
}