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//! Conversion from `u64` into [`U320`].
use super::U320;
/// Creates a [`U320`] from a `u64` value, placing it in the least
/// significant limb with the upper four limbs set to zero.
///
/// # Examples
///
/// ```
/// use cnfy_uint::u320::U320;
///
/// let v = U320::from(42u64);
/// assert_eq!(v, U320::from_be_limbs([0, 0, 0, 0, 42]));
/// ```
impl From<u64> for U320 {
#[inline]
fn from(value: u64) -> Self {
Self::from_be_limbs([0, 0, 0, 0, value])
}
}
#[cfg(test)]
mod ai_tests {
use super::*;
/// Converting zero produces U320::ZERO.
#[test]
fn zero() {
assert_eq!(U320::from(0u64), U320::ZERO);
}
/// Converting one produces U320::ONE.
#[test]
fn one() {
assert_eq!(U320::from(1u64), U320::ONE);
}
/// Converting u64::MAX fills only the lowest limb.
#[test]
fn max_u64() {
assert_eq!(
U320::from(u64::MAX),
U320::from_be_limbs([0, 0, 0, 0, u64::MAX]),
);
}
/// Arbitrary value round-trips through to_be_limbs.
#[test]
fn round_trip() {
let v = U320::from(0xDEADBEEFu64);
assert_eq!(v.to_be_limbs(), [0, 0, 0, 0, 0xDEADBEEF]);
}
}