Trait rug::ops::AddFromRound [−] [src]

pub trait AddFromRound<Lhs = Self> {
    type Round;
    type Ordering;
    fn add_from_round(&mut self, lhs: Lhs, round: Self::Round) -> Self::Ordering;
}

Compound addition and assignment to the rhs operand with a specified rounding method.

Examples

use rug::Float;
use rug::float::Round;
use rug::ops::{AddAssignRound, AddFromRound};
use std::cmp::Ordering;
struct F(f64);
impl AddFromRound<f64> for F {
    type Round = Round;
    type Ordering = Ordering;
    fn add_from_round(&mut self, lhs: f64, round: Round) -> Ordering {
        let mut f = Float::with_val(53, lhs);
        let dir = f.add_assign_round(self.0, round);
        self.0 = f.to_f64();
        dir
    }
}
let mut f = F(5.0);
let dir = f.add_from_round(3.0, Round::Nearest);
// 3.0 + 5.0 = 8.0
assert_eq!(f.0, 8.0);
assert_eq!(dir, Ordering::Equal);

Associated Types

The rounding method.

The direction from rounding.

Required Methods

Performs the addition.

Examples

use rug::Float;
use rug::float::Round;
use rug::ops::AddFromRound;
use std::cmp::Ordering;
// only four significant bits
let mut f = Float::with_val(4, -0.3);
let dir = f.add_from_round(-3, Round::Nearest);
// -3.3 rounded up to -3.25
assert_eq!(f, -3.25);
assert_eq!(dir, Ordering::Greater);

Implementors