Module average 

Average, AverageAssign, AverageRound, and AverageRoundAssign, traits for computing the average (arithmetic mean) of two numbers without overflow.

average

use malachite_base::num::arithmetic::traits::Average;

assert_eq!(4u8.average(6), 5);
// 4.5 rounds to the even neighbor, 4
assert_eq!(4u8.average(5), 4);
// 5.5 rounds to the even neighbor, 6
assert_eq!(5u8.average(6), 6);
assert_eq!((-5i8).average(-6), -6);
assert_eq!(u8::MAX.average(u8::MAX - 2), 254);

// for floats, the average is correctly rounded and cannot overflow
assert_eq!(1.0f64.average(2.0), 1.5);
assert_eq!(f64::MAX.average(f64::MAX), f64::MAX);
assert_eq!(f64::MAX.average(0.0), f64::MAX / 2.0);
assert_eq!(f32::INFINITY.average(1.0), f32::INFINITY);
assert!(f32::INFINITY.average(f32::NEG_INFINITY).is_nan());

average_assign

use malachite_base::num::arithmetic::traits::AverageAssign;

let mut x = 4u8;
x.average_assign(6);
assert_eq!(x, 5);

let mut x = -5i8;
x.average_assign(-6);
assert_eq!(x, -6);

let mut x = 1.0f64;
x.average_assign(2.0);
assert_eq!(x, 1.5);

average_round

use malachite_base::num::arithmetic::traits::AverageRound;
use malachite_base::rounding_modes::RoundingMode::*;
use std::cmp::Ordering::*;

assert_eq!(4u8.average_round(7, Floor), (5, Less));
assert_eq!(4u8.average_round(7, Ceiling), (6, Greater));
assert_eq!(4u8.average_round(7, Down), (5, Less));
assert_eq!(4u8.average_round(6, Exact), (5, Equal));

// the exact average is -5.5
assert_eq!((-4i8).average_round(-7, Down), (-5, Greater));
assert_eq!((-4i8).average_round(-7, Up), (-6, Less));

// the exact average is -0.5
assert_eq!(i8::MIN.average_round(i8::MAX, Floor), (-1, Less));
assert_eq!(i8::MIN.average_round(i8::MAX, Nearest), (0, Greater));

average_round_assign

use malachite_base::num::arithmetic::traits::AverageRoundAssign;
use malachite_base::rounding_modes::RoundingMode::*;
use std::cmp::Ordering::*;

let mut x = 4u8;
assert_eq!(x.average_round_assign(7, Floor), Less);
assert_eq!(x, 5);

let mut x = -4i8;
assert_eq!(x.average_round_assign(-7, Up), Less);
assert_eq!(x, -6);