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use crate::{DekuError, DekuRead, DekuWrite};
use bitvec::prelude::*;
impl<'a, T: DekuRead<'a, Ctx>, Ctx: Copy> DekuRead<'a, Ctx> for Option<T> {
/// Read a T from input and store as Some(T)
/// * `inner_ctx` - The context required by `T`. It will be passed to every `T`s when constructing.
/// # Examples
/// ```rust
/// # use deku::ctx::*;
/// # use deku::DekuRead;
/// # use deku::bitvec::BitView;
/// let input = vec![1u8, 2, 3, 4];
/// let (rest, v) = Option::<u32>::read(input.view_bits(), Endian::Little).unwrap();
/// assert!(rest.is_empty());
/// assert_eq!(v, Some(0x04030201))
/// ```
fn read(
input: &'a BitSlice<Msb0, u8>,
inner_ctx: Ctx,
) -> Result<(&'a BitSlice<Msb0, u8>, Self), DekuError>
where
Self: Sized,
{
let (rest, val) = <T>::read(input, inner_ctx)?;
Ok((rest, Some(val)))
}
}
impl<T: DekuWrite<Ctx>, Ctx: Copy> DekuWrite<Ctx> for Option<T> {
/// Write T if Some
/// * **inner_ctx** - The context required by `T`.
/// # Examples
/// ```rust
/// # use deku::{ctx::Endian, DekuWrite};
/// # use deku::bitvec::{bitvec, Msb0};
/// let data = Some(1u8);
/// let mut output = bitvec![Msb0, u8;];
/// data.write(&mut output, Endian::Big).unwrap();
/// assert_eq!(output, bitvec![Msb0, u8; 0, 0, 0, 0, 0, 0, 0, 1])
/// ```
fn write(&self, output: &mut BitVec<Msb0, u8>, inner_ctx: Ctx) -> Result<(), DekuError> {
self.as_ref().map_or(Ok(()), |v| v.write(output, inner_ctx))
}
}