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//! Bitwise AND via the [`BitAnd`] trait.
use super::U384;
use core::ops::BitAnd;
/// Computes the bitwise AND of two 384-bit integers, producing a
/// result where each bit is set only if both corresponding input bits
/// are set.
///
/// Applied independently to each of the six `u64` limbs.
///
/// # Examples
///
/// ```
/// use cnfy_uint::u384::U384;
///
/// let a = U384::from_be_limbs([0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]);
/// let b = U384::from_be_limbs([0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F]);
/// assert_eq!(a & b, U384::from_be_limbs([0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F]));
/// ```
impl BitAnd for U384 {
type Output = U384;
#[inline]
fn bitand(self, rhs: U384) -> U384 {
U384([
self.0[0] & rhs.0[0],
self.0[1] & rhs.0[1],
self.0[2] & rhs.0[2],
self.0[3] & rhs.0[3],
self.0[4] & rhs.0[4],
self.0[5] & rhs.0[5],
])
}
}
#[cfg(test)]
mod ai_tests {
use super::*;
/// AND with self is identity.
#[test]
fn self_identity() {
let a = U384::from_be_limbs([0x1234, 0x5678, 0x9ABC, 0xDEF0, 0x1111, 0x2222]);
assert_eq!(a & a, a);
}
/// AND with zero is zero.
#[test]
fn and_zero() {
let a = U384::from_be_limbs([0x1234, 0x5678, 0x9ABC, 0xDEF0, 0x1111, 0x2222]);
assert_eq!(a & U384::ZERO, U384::ZERO);
}
/// AND with MAX is identity.
#[test]
fn and_max() {
let a = U384::from_be_limbs([0x1234, 0x5678, 0x9ABC, 0xDEF0, 0x1111, 0x2222]);
assert_eq!(a & U384::MAX, a);
}
/// AND is commutative.
#[test]
fn commutative() {
let a = U384::from_be_limbs([1, 2, 3, 4, 5, 6]);
let b = U384::from_be_limbs([7, 8, 9, 10, 11, 12]);
assert_eq!(a & b, b & a);
}
/// Masking extracts specific bits.
#[test]
fn mask() {
let a = U384::from_be_limbs([0xFF00, 0, 0, 0, 0, 0]);
let mask = U384::from_be_limbs([0x0F00, 0, 0, 0, 0, 0]);
assert_eq!(a & mask, U384::from_be_limbs([0x0F00, 0, 0, 0, 0, 0]));
}
}