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/*
Copyright 2016 Martin Buck
This file is part of rust-3d.
rust-3d is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
rust-3d is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with rust-3d. If not, see <http://www.gnu.org/licenses/>.
*/
//! Positive, a wrapper for a f64 value, ensuring it is always > 0
use std::fmt;
use std::ops::{Add, AddAssign, Mul, MulAssign};
use std::hash::{Hash, Hasher};
use prelude::*;
#[derive (Debug, PartialEq, PartialOrd, Clone, Copy)]
/// Positive, a wrapper for a f64 value, ensuring it is always > 0
pub struct Positive {
val: f64
}
impl Positive {
/// Creates a new Positive if input > 0, fails otherwise
pub fn new(val: f64) -> Result<Positive> {
if val > 0.0 {
return Ok(Positive {val});
}
Err(ErrorKind::NumberInWrongRange)
}
/// Creates a new Positive with value 1
pub fn one() -> Positive {
Positive {val : 1.0}
}
/// Returns the wrapped value
pub fn get(&self) -> f64 {
self.val
}
/// Returns the square root
pub fn sqrt(&self) -> Positive {
Positive{val: self.val.sqrt()}
}
}
impl Eq for Positive {}
impl Hash for Positive {
fn hash<H: Hasher>(&self, state: &mut H) {
(self.val as u64).hash(state);
}
}
impl Add for Positive {
type Output = Positive;
fn add(self, other: Positive) -> Positive {
Positive {val: self.val + other.val}
}
}
impl Add<NonNegative> for Positive {
type Output = Positive;
fn add(self, other: NonNegative) -> Positive {
Positive { val: self.val + other.get() }
}
}
impl AddAssign for Positive {
fn add_assign(&mut self, other: Positive) {
self.val += other.val;
}
}
impl AddAssign<NonNegative> for Positive {
fn add_assign(&mut self, other: NonNegative) {
self.val += other.get();
}
}
impl Mul for Positive {
type Output = Positive;
fn mul(self, other: Positive) -> Positive {
Positive {val: self.val * other.val }
}
}
impl MulAssign for Positive {
fn mul_assign(&mut self, other: Positive) {
self.val *= other.get();
}
}
impl Default for Positive {
fn default() -> Self {
Self::one()
}
}
impl fmt::Display for Positive {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.val)
}
}