Templates Variadics Snippets

#include <iostream>

using std::cout;
using std::endl;

template <int... Args>
struct StaticArray
{
    static const unsigned int size = sizeof...(Args);
    int array[sizeof...(Args)] = {Args...};
};

template <class C, class... Args>
C * make_new(Args&&... args)
{
    return new C(std::forward<Args>(args)...);
}

template<typename T> T sum(const T& t) { return t; }
template<typename T, typename... Args> T sum(const T& val, const Args&... rest)
{
    return val + sum(rest...);
}

template <class... Ts>
size_t sizeofSum()
{
    size_t sum = 0;
    for(size_t s : {sizeof(Ts)...})
        sum += s;
    return sum;
}

template<int x> struct T {
    static const int var = x;
};
template<typename... Args> bool staticMemberAllEqualTo(int value)
{
    bool ret = true;
    using Expand = int[];
    (void)Expand{0, (void(Args::var == value ? 0 : (ret = false)), 0)...};
    return ret;
}
// c++17 way
//template <class... Is> bool checkAllArgs(Is... args) {
//    return ((args == 5) && ...);
//}
template<typename... Args>
void setStaticMembersTo(int x)
{
    [](...){}((Args::var = x)...);
}

int main()
{
    StaticArray<1, 2, 3, 4> t;
    int * ptr = make_new<int>(123);
    cout << sum(1, 2, 3, 4) << endl;
    cout << sizeofSum<double, int, short, char>() << endl;
    cout << staticMemberAllEqualTo< T<5>, T<5>, T<5> >(5) << endl;
    //cout << checkAllArgs(5, 5, 5) << endl;

    delete ptr;
    return 0;
}