add function to attempt to change base

This commit is contained in:
Corwin 2022-08-06 18:35:29 +01:00
parent ca9c898c14
commit 5d2161c318

View file

@ -5,6 +5,7 @@
use core::{
cmp::{Eq, Ord, PartialEq, PartialOrd},
fmt::{Debug, Display},
mem::size_of,
ops::{
Add, AddAssign, BitAnd, Div, DivAssign, Mul, MulAssign, Neg, Not, Rem, RemAssign, Shl, Shr,
Sub, SubAssign,
@ -298,6 +299,32 @@ impl<I: FixedWidthUnsignedInteger, const N: usize> Num<I, N> {
}
}
/// Attempts to perform the conversion between two integer types and between
/// two different fractional precisions
pub fn try_change_base<J: FixedWidthUnsignedInteger + TryFrom<I>, const M: usize>(
self,
) -> Option<Num<J, M>> {
if size_of::<I>() > size_of::<J>() {
// I bigger than J, perform the shift in I to preserve precision
let n = if N < M {
self.0 << (M - N)
} else {
self.0 >> (N - M)
};
let n = n.try_into().ok()?;
Some(Num(n))
} else {
// J bigger than I, perform the shift in J to preserve precision
let n: J = self.0.try_into().ok()?;
let n = if N < M { n << (M - N) } else { n >> (N - M) };
Some(Num(n))
}
}
/// A bit for bit conversion from a number to a fixed num
pub fn from_raw(n: I) -> Self {
Num(n)