Function mp_rat_to_decimal

pub unsafe extern "C" fn mp_rat_to_decimal(
    r: mp_rat,
    radix: mp_size,
    prec: mp_size,
    round: mp_round_mode,
    str_: *mut c_char,
    limit: c_int,
) -> mp_result

Converts the value of r to a string in decimal-point notation with the specified radix, writing no more than limit bytes of data to the given output buffer. It generates prec digits of precision, and requires MP_MIN_RADIX <= radix <= MP_MAX_RADIX.

Ratios usually must be rounded when they are being converted for output as a decimal value. There are four rounding modes currently supported:

MP_ROUND_DOWN Truncates the value toward zero. Example: 12.009 to 2dp becomes 12.00

MP_ROUND_UP Rounds the value away from zero: Example: 12.001 to 2dp becomes 12.01, but 12.000 to 2dp remains 12.00

MP_ROUND_HALF_DOWN Rounds the value to nearest digit, half goes toward zero. Example: 12.005 to 2dp becomes 12.00, but 12.006 to 2dp becomes 12.01

MP_ROUND_HALF_UP Rounds the value to nearest digit, half rounds upward. Example: 12.005 to 2dp becomes 12.01, but 12.004 to 2dp becomes 12.00