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//! Construction of a `U320` from a five-element `[u64; 5]` limb array.
use super::U320;
impl U320 {
/// Creates a new [`U320`] from a five-element array of `u64` limbs in
/// big-endian order: `[w0, w1, w2, w3, w4]` where `w0` is the most
/// significant and `w4` is the least significant.
///
/// The input is reversed into the internal little-endian layout.
///
/// # Examples
///
/// ```
/// use cnfy_uint::u320::U320;
///
/// let value = U320::from_be_limbs([0, 0, 0, 0, 42]);
/// assert_eq!(value.to_be_limbs(), [0, 0, 0, 0, 42]);
/// ```
#[inline]
pub const fn from_be_limbs(value: [u64; 5]) -> Self {
Self([value[4], value[3], value[2], value[1], value[0]])
}
}
#[cfg(test)]
mod ai_tests {
use super::*;
/// Constructing from five zeros yields a zero value.
#[test]
fn zero() {
let z = U320::from_be_limbs([0, 0, 0, 0, 0]);
assert_eq!(z, U320::ZERO);
}
/// All limbs are stored in reversed (little-endian) positions.
#[test]
fn limb_order() {
let v = U320::from_be_limbs([1, 2, 3, 4, 5]);
assert_eq!(v.0[0], 5); // LSB
assert_eq!(v.0[4], 1); // MSB
}
/// Maximum value fills all five limbs.
#[test]
fn max_value() {
let v = U320::from_be_limbs([u64::MAX; 5]);
assert_eq!(v, U320::MAX);
}
}