Macro diyfp

macro_rules! diyfp {
    (
        floating_type: $fty:ty,
        significand_type: $sigty:ty,
        exponent_type: $expty:ty,

        diy_significand_size: $diy_significand_size:expr,
        significand_size: $significand_size:expr,
        exponent_bias: $exponent_bias:expr,
        mask_type: $mask_type:ty,
        exponent_mask: $exponent_mask:expr,
        significand_mask: $significand_mask:expr,
        hidden_bit: $hidden_bit:expr,
        cached_powers_f: $cached_powers_f:expr,
        cached_powers_e: $cached_powers_e:expr,
        min_power: $min_power:expr,
    ) => { ... };
}