variadic variadic template template parameters

http://stackoverflow.com/questions/38611823/variadic-variadic-template-template-parameters-parameters

include <array>

template <typename T, std::size_t ... Args>

struct testS

{ };

void foo ()

{ /* terminal iteration */ }

template <template <typename, std::size_t...> class Pack,

typename T, std::size_t ... Args, typename ... Packs>

void foo (const Pack<T, Args...> pack0, Packs ... packs) // 是不是Pack中的T, 和Args... 必须在前面声明中体现出来

{

// do something with pack0

foo(packs...);

}

int main()

{

foo(testS<int>{}, std::array<long, 5U>{}, testS<char, 7U, 9U, 11U>{});

return 0;

}

------------------------------------------------------------------------------------------------------------

#include <array>

#include <tuple>

using namespace std;

template <typename T>

struct extract_args;

template <template <typename, size_t...> class Pack, typename T, size_t... Args>

struct extract_args<Pack<T,Args...>>

{

using type = T;

using args = std::index_sequence<Args...>;

};

template<typename... Ts>

void foo(const Ts&... packs)

{

using all_ts = std::tuple<typename extract_args<Ts>::type...>;

all_ts a;

}