if constexpr to switch type

if_constexpr_type.cpp

// if constexpr to switch type
// 
template<uint8_t N>
struct _buf_type
{
    static_assert(N > 0,   "Buffer must be more then 0");
    static_assert(N <= 64, "Maximum buffer size is 64");
    constexpr static auto _i2t()
    {
        if      constexpr (N <= 8 ) {return uint8_t(0) ;}
        else if constexpr (N <= 16) {return uint16_t(0);}
        else if constexpr (N <= 32) {return uint32_t(0);}
        else if constexpr (N <= 64) {return uint64_t(0);}
    }
public:
    using type = decltype(_i2t());
};

// Using:
// using data_type = typename _buf_type<N>::type;