The second improved version of has_type. It's shorter, does away with recursion and uses the bool_sequence idiom.

has_type_v2.cpp

#include <type_traits>
#include <tuple>

template <bool...>
struct bool_sequence { };

template <bool... Bs>
using bool_and = std::is_same<bool_sequence<Bs...>,
                              bool_sequence<(Bs || true)...>>;

template <bool... Bs>
using bool_or = std::integral_constant<bool, !bool_and<!Bs...>::value>;

namespace detail
{
    template <typename value, typename tuple>
    struct has_type;
        
    template <typename value, typename... xs>
    struct has_type<value, std::tuple<xs...>>
    {
        using type = bool_or<std::is_same<xs, value>::value...>;
    };
}

template <typename value, typename tuple>
using has_type_t = typename detail::has_type<value, std::decay_t<tuple>>::type;

template <typename value, typename tuple>
constexpr auto has_type(tuple&&) -> has_type_t<value, tuple>
{
    return {};
}

int main()
{
    constexpr std::tuple<bool, double, int, short> t;
    static_assert(has_type<int>(t), "");
}