xeos
/
num-traits
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

De-generalize `twos_complement' helper function

This commit is contained in:
Eduardo Pinho 2017-06-20 01:31:49 +01:00
parent 61cfdc37b3
commit 15f9334955
1 changed files with 6 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
bigint/src/bigint.rs
View File

@ -1,5 +1,5 @@
use std::default::Default; use std::default::Default;
use std::ops::{Add, Div, Mul, Neg, Rem, Shl, Shr, Sub, Not, DerefMut}; use std::ops::{Add, Div, Mul, Neg, Rem, Shl, Shr, Sub, Not};
use std::str::{self, FromStr}; use std::str::{self, FromStr};
use std::fmt; use std::fmt;
use std::cmp::Ordering::{self, Less, Greater, Equal}; use std::cmp::Ordering::{self, Less, Greater, Equal};
@ -16,7 +16,7 @@ use serde;
use rand::Rng; use rand::Rng;
use integer::Integer; use integer::Integer;
use traits::{ToPrimitive, FromPrimitive, Num, WrappingAdd, CheckedAdd, CheckedSub, use traits::{ToPrimitive, FromPrimitive, Num, CheckedAdd, CheckedSub,
CheckedMul, CheckedDiv, Signed, Zero, One}; CheckedMul, CheckedDiv, Signed, Zero, One};
use self::Sign::{Minus, NoSign, Plus}; use self::Sign::{Minus, NoSign, Plus};
@ -1214,16 +1214,14 @@ fn twos_complement_be(digits: &mut [u8]) {
/// Perform in-place two's complement of the given digit iterator /// Perform in-place two's complement of the given digit iterator
/// starting from the least significant byte. /// starting from the least significant byte.
#[inline] #[inline]
fn twos_complement<T, R, I>(digits: I) fn twos_complement<'a, I>(digits: I)
where I: IntoIterator<Item = R>, where I: IntoIterator<Item = &'a mut u8>
R: DerefMut<Target = T>,
T: Clone + Not<Output = T> + WrappingAdd + Zero + One
{ {
let mut carry = true; let mut carry = true;
for mut d in digits { for mut d in digits {
*d = d.clone().not(); *d = d.not();
if carry { if carry {
*d = d.wrapping_add(&T::one()); *d = d.wrapping_add(1);
carry = d.is_zero(); carry = d.is_zero();
} }
} }