提交 d431a67c 编写于 作者: B Brendan Zabarauskas

Move saturating operator methods into Int

上级 d1eb68e8
......@@ -62,7 +62,7 @@ trait defined in this module. For loops can be viewed as a syntactical expansion
use cmp;
use cmp::{PartialEq, PartialOrd, Ord};
use mem;
use num::{Zero, One, CheckedAdd, CheckedSub, Saturating, ToPrimitive, Int};
use num::{Zero, One, CheckedAdd, CheckedSub, ToPrimitive, Int};
use ops::{Add, Mul, Sub};
use option::{Option, Some, None};
use uint;
......
......@@ -525,6 +525,28 @@ fn to_be(self) -> Self { // or not to be?
fn to_le(self) -> Self {
if cfg!(target_endian = "little") { self } else { self.swap_bytes() }
}
/// Saturating addition. Returns `self + other`, saturating at the
/// numeric bounds instead of overflowing.
#[inline]
fn saturating_add(self, other: Self) -> Self {
match self.checked_add(&other) {
Some(x) => x,
None if other >= Zero::zero() => Bounded::max_value(),
None => Bounded::min_value(),
}
}
/// Saturating subtraction. Returns `self - other`, saturating at the
/// numeric bounds instead of overflowing.
#[inline]
fn saturating_sub(self, other: Self) -> Self {
match self.checked_sub(&other) {
Some(x) => x,
None if other >= Zero::zero() => Bounded::min_value(),
None => Bounded::max_value(),
}
}
}
macro_rules! int_impl {
......@@ -1150,43 +1172,6 @@ fn from<N: ToPrimitive>(n: N) -> Option<$T> {
impl_num_cast!(f32, to_f32)
impl_num_cast!(f64, to_f64)
/// Saturating math operations
pub trait Saturating {
/// Saturating addition operator.
/// Returns a+b, saturating at the numeric bounds instead of overflowing.
fn saturating_add(self, v: Self) -> Self;
/// Saturating subtraction operator.
/// Returns a-b, saturating at the numeric bounds instead of overflowing.
fn saturating_sub(self, v: Self) -> Self;
}
impl<T: CheckedAdd + CheckedSub + Zero + PartialOrd + Bounded> Saturating for T {
#[inline]
fn saturating_add(self, v: T) -> T {
match self.checked_add(&v) {
Some(x) => x,
None => if v >= Zero::zero() {
Bounded::max_value()
} else {
Bounded::min_value()
}
}
}
#[inline]
fn saturating_sub(self, v: T) -> T {
match self.checked_sub(&v) {
Some(x) => x,
None => if v >= Zero::zero() {
Bounded::min_value()
} else {
Bounded::max_value()
}
}
}
}
/// Performs addition that returns `None` instead of wrapping around on overflow.
pub trait CheckedAdd: Add<Self, Self> {
/// Adds two numbers, checking for overflow. If overflow happens, `None` is returned.
......
......@@ -40,7 +40,7 @@
use cmp;
use default::Default;
use iter::*;
use num::{CheckedAdd, Saturating, div_rem};
use num::{CheckedAdd, Int, div_rem};
use ops;
use option::{None, Option, Some};
use ptr;
......
......@@ -25,7 +25,7 @@
use iter::{DoubleEndedIterator, ExactSize};
use iter::range;
use kinds::Sized;
use num::{CheckedMul, Saturating};
use num::{CheckedMul, Int};
use option::{Option, None, Some};
use raw::Repr;
use slice::{mod, SlicePrelude};
......
......@@ -23,7 +23,7 @@
pub use core::num::{Num, div_rem, Zero, zero, One, one};
pub use core::num::{Signed, abs, signum};
pub use core::num::{Unsigned, pow, Bounded};
pub use core::num::{Primitive, Int, UnsignedInt, Saturating};
pub use core::num::{Primitive, Int, UnsignedInt};
pub use core::num::{CheckedAdd, CheckedSub, CheckedMul, CheckedDiv};
pub use core::num::{cast, FromPrimitive, NumCast, ToPrimitive};
pub use core::num::{next_power_of_two, is_power_of_two};
......
......@@ -106,7 +106,6 @@ enum NamePadding { PadNone, PadOnLeft, PadOnRight }
impl TestDesc {
fn padded_name(&self, column_count: uint, align: NamePadding) -> String {
use std::num::Saturating;
let mut name = String::from_str(self.name.as_slice());
let fill = column_count.saturating_sub(name.len());
let mut pad = " ".repeat(fill);
......
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