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

pub trait MulFromRound<Lhs = Self> {
    type Round;
    type Ordering;
    fn mul_from_round(&mut self, rhs: Lhs, round: Self::Round) -> Self::Ordering;
}

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

Examples

use rug::Float;
use rug::float::Round;
use rug::ops::{MulAssignRound, MulFromRound};
use std::cmp::Ordering;
struct F(f64);
impl MulFromRound<f64> for F {
    type Round = Round;
    type Ordering = Ordering;
    fn mul_from_round(&mut self, lhs: f64, round: Round) -> Ordering {
        let mut f = Float::with_val(53, lhs);
        let dir = f.mul_assign_round(self.0, round);
        self.0 = f.to_f64();
        dir
    }
}
let mut f = F(5.0);
let dir = f.mul_from_round(3.0, Round::Nearest);
// 3.0 * 5.0 = 15.0
assert_eq!(f.0, 15.0);
assert_eq!(dir, Ordering::Equal);

Associated Types

The rounding method.

The direction from rounding.

Required Methods

Performs the multiplication.

Examples

use rug::Float;
use rug::float::Round;
use rug::ops::MulFromRound;
use std::cmp::Ordering;
// only four significant bits
let mut f = Float::with_val(4, 13);
let dir = f.mul_from_round(-3, Round::Nearest);
// -39 rounded down to -40
assert_eq!(f, -40);
assert_eq!(dir, Ordering::Less);

Implementors