compile time array concat

#include <iterator>
#include <algorithm>
#include <array>

using namespace std;


namespace impl {

    template<class T, size_t N1, size_t N2>
    array<T, N1 + N2>
    constexpr operator >>(const array<T, N1>& array1, const array<T, N2>& array2) {
        array<T, N1 + N2> result {};

        copy(array1.begin(), array1.end(), result.begin());
        copy(array2.begin(), array2.end(), result.begin() + array1.size());
        return result;
    }

    template<class... Args>
    constexpr auto concat(Args&&... args) {
        return (... >> args);
    }
}

using impl::concat;

int main() {
    constexpr array a {1, 2, 3, 4};
    constexpr array b {4, 5, 6};

    constexpr auto a_and_b = concat(a, b, a, b);

    static_assert(a_and_b.size() == 14);
    static_assert(a_and_b[5] == 5);
    static_assert(a_and_b[12] == 5);
}