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use crate::traits::Capacity;
pub type Cow<'a, T> = crate::generic::Cow<'a, T, Lean>;
pub(crate) mod internal {
#[derive(Clone, Copy, PartialEq, Eq)]
pub struct Lean;
}
use internal::Lean;
const MASK_LO: usize = u32::max_value() as usize;
const MASK_HI: usize = !(u32::max_value() as usize);
impl Lean {
#[inline]
pub const fn mask_len(len: usize) -> usize {
len & MASK_LO
}
}
impl Capacity for Lean {
type Field = Lean;
type NonZero = Lean;
#[inline]
fn len(fat: usize) -> usize {
fat & MASK_LO
}
#[inline]
fn empty(len: usize) -> (usize, Lean) {
(len & MASK_LO, Lean)
}
#[inline]
fn store(len: usize, capacity: usize) -> (usize, Lean) {
if capacity & MASK_HI != 0 {
panic!("beef::lean::Cow: Capacity out of bounds");
}
let fat = ((capacity & MASK_LO) << 32) | (len & MASK_LO);
(fat, Lean)
}
#[inline]
fn unpack(fat: usize, _: Lean) -> (usize, usize) {
(fat & MASK_LO, (fat & MASK_HI) >> 32)
}
#[inline]
fn maybe(fat: usize, _: Lean) -> Option<Lean> {
if fat & MASK_HI != 0 {
Some(Lean)
} else {
None
}
}
}