Module malachite_base::num::arithmetic::log_base_2

Traits for taking the base-2 logarithm of a number.

The traits are FloorLogBase2, CeilingLogBase2, and CheckedLogBase2.

floor_log_base_2

use malachite_base::num::arithmetic::traits::FloorLogBase2;

assert_eq!(1u8.floor_log_base_2(), 0);
assert_eq!(100u64.floor_log_base_2(), 6);

assert_eq!(1.0f32.floor_log_base_2(), 0);
assert_eq!(100.0f32.floor_log_base_2(), 6);
assert_eq!(0.1f32.floor_log_base_2(), -4);

ceiling_log_base_2

use malachite_base::num::arithmetic::traits::CeilingLogBase2;

assert_eq!(1u8.ceiling_log_base_2(), 0);
assert_eq!(100u64.ceiling_log_base_2(), 7);

assert_eq!(1.0f32.ceiling_log_base_2(), 0);
assert_eq!(100.0f32.ceiling_log_base_2(), 7);
assert_eq!(0.1f32.ceiling_log_base_2(), -3);

checked_log_base_2

use malachite_base::num::arithmetic::traits::CheckedLogBase2;

assert_eq!(1u8.checked_log_base_2(), Some(0));
assert_eq!(100u64.checked_log_base_2(), None);
assert_eq!(128u64.checked_log_base_2(), Some(7));

assert_eq!(1.0f32.checked_log_base_2(), Some(0));
assert_eq!(100.0f32.checked_log_base_2(), None);
assert_eq!(128.0f32.checked_log_base_2(), Some(7));
assert_eq!(0.1f32.checked_log_base_2(), None);
assert_eq!(0.0625f32.checked_log_base_2(), Some(-4));