Function ulp 

pub fn ulp(x: &DBig) -> OxiNumResult<DBig>

Return the unit in the last place of x at its current precision.

This is dashu_float::FBig::ulp re-exported as a free function for API symmetry with epsilon and with_precision. The result is a positive value whose least significant decimal position matches x (i.e. ulp(x) is the smallest positive d such that x + d is the next representable neighbour of x).

Errors

Returns OxiNumError::Precision if x carries unlimited precision (x.precision() == 0). In that case ulp is undefined — dashu_float::FBig::ulp would itself panic, which we surface as a recoverable error here.

Examples

use std::str::FromStr;
use oxinum_float::{precision::ulp, DBig};

let x = DBig::from_str("1.23").expect("parse 1.23");
let u = ulp(&x).expect("finite precision");
assert_eq!(u, DBig::from_str("0.01").expect("parse 0.01"));
// ulp does not change the carried precision.
assert_eq!(u.precision(), x.precision());