A Decimal implementation written in pure Rust suitable for financial calculations that require significant integral and fractional digits with no round-off errors.
The binary representation consists of a 96 bit integer number, a scaling factor used to specify the decimal fraction and a 1 bit sign. Because of this representation, trailing zeros are preserved and may be exposed when in string form. These can be truncated using the normalize or round_dp functions.
Decimal numbers can be created in a few distinct ways. The easiest and most optimal method of creating a Decimal is to use the procedural macro within the rust_decimal_macros crate:
// Procedural macros need importing directly
use rust_decimal_macros::*;
let number = dec!(-1.23);Alternatively you can also use one of the Decimal number convenience functions:
use rust_decimal::Decimal;
// Using an integer followed by the decimal points
let scaled = Decimal::new(202, 2); // 2.02
// From a string representation
let from_string = Decimal::from_str("2.02").unwrap(); // 2.02
// Using the `Into` trait
let my_int : Decimal = 3i32.into();
// Using the raw decimal representation
// 3.1415926535897932384626433832
let pi = Decimal::from_parts(1102470952, 185874565, 1703060790, false, 28);