pub trait MathUtils {
fn log2_trunc(self) -> Self;
fn sqrt_floor(self) -> Self;
fn sqrt_ceil(self) -> Self;
}
macro_rules! impl_digit_utils(($($ty:ty),*) => {
$(
impl MathUtils for $ty {
#[inline]
fn log2_trunc(self) -> Self {
(self as f64).log2().trunc() as Self
}
#[inline]
fn sqrt_floor(self) -> Self {
(self as f64).sqrt() as Self
}
#[inline]
fn sqrt_ceil(self) -> Self {
let tmp = (self as f64).sqrt() as Self;
if tmp * tmp == self {
tmp
} else {
tmp + 1
}
}
}
)*
});
impl_digit_utils!(u64, u32, i64, i32, usize, isize);
#[cfg(test)]
mod tests {
use super::*;
macro_rules! impl_math_tests (($ty:ty) => {
assert_eq!((16 as $ty).log2_trunc(), 4);
assert_eq!((10 as $ty).log2_trunc(), 3);
assert_eq!((9 as $ty).sqrt_floor(), 3);
assert_eq!((10 as $ty).sqrt_floor(), 3);
assert_eq!((15 as $ty).sqrt_floor(), 3);
assert_eq!((9 as $ty).sqrt_ceil(), 3);
assert_eq!((10 as $ty).sqrt_ceil(), 4);
assert_eq!((10 as $ty).sqrt_ceil(), 4);
});
#[test]
fn u64_math_test() {
impl_math_tests!(u64);
}
#[test]
fn u32_math_test() {
impl_math_tests!(u32);
}
#[test]
fn i64_math_test() {
impl_math_tests!(i64);
}
#[test]
fn i32_math_test() {
impl_math_tests!(i32);
}
#[test]
fn usize_math_test() {
impl_math_tests!(usize);
}
#[test]
fn isize_math_test() {
impl_math_tests!(isize);
}
}