cmp: switch min and max to TotalOrd

The `Float` trait provides correct `min` and `max` methods on floating
point types, providing a consistent result regardless of the order the
parameters are passed.

These generic functions do not take the necessary performance hit to
correctly support a partial order, so the true requirement should be
given as a type bound.

Closes #12712
This commit is contained in:
Daniel Micay 2014-03-08 01:10:32 -05:00
parent 3fbee34a89
commit 4e1c2158f2
4 changed files with 7 additions and 9 deletions

View File

@ -353,8 +353,6 @@ fn pnorm(nums: &~[f64], p: uint) -> f64 {
fn main() {
let numbers = vec::from_fn(1000000, |_| rand::random::<f64>());
println!("Inf-norm = {}", *numbers.iter().max().unwrap());
let numbers_arc = Arc::new(numbers);
for num in range(1u, 10) {

View File

@ -184,12 +184,12 @@ pub trait Equiv<T> {
}
#[inline]
pub fn min<T:Ord>(v1: T, v2: T) -> T {
pub fn min<T: TotalOrd>(v1: T, v2: T) -> T {
if v1 < v2 { v1 } else { v2 }
}
#[inline]
pub fn max<T:Ord>(v1: T, v2: T) -> T {
pub fn max<T: TotalOrd>(v1: T, v2: T) -> T {
if v1 > v2 { v1 } else { v2 }
}

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@ -68,7 +68,7 @@ use cmp;
use num::{Zero, One, CheckedAdd, CheckedSub, Saturating, ToPrimitive, Int};
use option::{Option, Some, None};
use ops::{Add, Mul, Sub};
use cmp::{Eq, Ord};
use cmp::{Eq, Ord, TotalOrd};
use clone::Clone;
use uint;
use mem;
@ -626,7 +626,7 @@ pub trait Iterator<A> {
/// assert_eq!(*xs.iter().max_by(|x| x.abs()).unwrap(), -10);
/// ```
#[inline]
fn max_by<B: Ord>(&mut self, f: |&A| -> B) -> Option<A> {
fn max_by<B: TotalOrd>(&mut self, f: |&A| -> B) -> Option<A> {
self.fold(None, |max: Option<(A, B)>, x| {
let x_val = f(&x);
match max {
@ -650,7 +650,7 @@ pub trait Iterator<A> {
/// assert_eq!(*xs.iter().min_by(|x| x.abs()).unwrap(), 0);
/// ```
#[inline]
fn min_by<B: Ord>(&mut self, f: |&A| -> B) -> Option<A> {
fn min_by<B: TotalOrd>(&mut self, f: |&A| -> B) -> Option<A> {
self.fold(None, |min: Option<(A, B)>, x| {
let x_val = f(&x);
match min {
@ -917,7 +917,7 @@ pub trait OrdIterator<A> {
fn min_max(&mut self) -> MinMaxResult<A>;
}
impl<A: Ord, T: Iterator<A>> OrdIterator<A> for T {
impl<A: TotalOrd, T: Iterator<A>> OrdIterator<A> for T {
#[inline]
fn max(&mut self) -> Option<A> {
self.fold(None, |max, x| {

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@ -1069,7 +1069,7 @@ impl MetricMap {
if delta.abs() <= noise {
LikelyNoise
} else {
let pct = delta.abs() / cmp::max(vold.value, f64::EPSILON) * 100.0;
let pct = delta.abs() / vold.value.max(f64::EPSILON) * 100.0;
if vold.noise < 0.0 {
// When 'noise' is negative, it means we want
// to see deltas that go up over time, and can