template<typename T, std::size_t N>
inline SPROUT_CONSTEXPR std::size_t
hash_value(sprout::array<T, N> const& v);
#include <sprout/array.hpp>
using namespace sprout;
using type = array<int, 10>;
SPROUT_STATIC_CONSTEXPR auto input = type{{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}};
SPROUT_STATIC_CONSTEXPR auto h = sprout::to_hash(input);
static_assert(h, "hash value generated from array.");