Small Rust library for calculating greatest common divisor
crates.io/crates/gcd
Get rid of external dependencies (#10)
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-15
-1
Cargo.toml
-1
Cargo.toml
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-14
src/lib.rs
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src/lib.rs
···
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}
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macro_rules! gcd_impl {
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($($T:ty),*) => {$(
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($(($T:ty) $binary:ident $euclid:ident),*) => {$(
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paste::paste! {
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#[doc = "Const binary GCD implementation for `" $T "`."]
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pub const fn [<binary_ $T>](mut u: $T, mut v: $T) -> $T
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#[doc = concat!("Const binary GCD implementation for `", stringify!($T), "`.")]
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pub const fn $binary(mut u: $T, mut v: $T) -> $T
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{
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if u == 0 { return v; }
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if v == 0 { return u; }
···
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loop {
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v >>= v.trailing_zeros();
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#[allow(clippy::manual_swap)]
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if u > v {
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// mem::swap(&mut u, &mut v);
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let temp = u;
···
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u << shift
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}
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#[doc = "Const euclid GCD implementation for `" $T "`."]
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pub const fn [<euclid_ $T>]( a: $T, b: $T) -> $T
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#[doc = concat!("Const euclid GCD implementation for `", stringify!($T), "`.")]
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pub const fn $euclid( a: $T, b: $T) -> $T
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{
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// variable names based off euclidean division equation: a = b · q + r
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let (mut a, mut b) = if a > b {
···
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(b, a)
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};
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#[allow(clippy::manual_swap)]
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while b != 0 {
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// mem::swap(&mut a, &mut b);
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let temp = a;
···
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a
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}
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}
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impl Gcd for $T {
···
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}
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fn gcd_binary(self, v: $T) -> $T {
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paste::paste! {
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[<binary_ $T>](self, v)
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}
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$binary(self, v)
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}
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fn gcd_euclid(self, other: $T) -> $T {
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paste::paste! {
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[<euclid_ $T>](self, other)
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}
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$euclid(self, other)
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}
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}
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)*};
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}
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gcd_impl! { u8, u16, u32, u64, u128, usize }
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gcd_impl! {
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(u8) binary_u8 euclid_u8,
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(u16) binary_u16 euclid_u16,
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(u32) binary_u32 euclid_u32,
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(u64) binary_u64 euclid_u64,
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(u128) binary_u128 euclid_u128,
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(usize) binary_usize euclid_usize
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}
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#[cfg(test)]
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mod test {