1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62
use crate::{NumBytes, Read, ReadError, Write, WriteError}; #[derive(Clone, Default, Debug)] pub struct BinaryExtension<T>(Option<T>); impl<T> NumBytes for BinaryExtension<T> where T: NumBytes, { fn num_bytes(&self) -> usize { self.0.as_ref().map(|t| t.num_bytes()).unwrap_or_default() } } impl<T> Read for BinaryExtension<T> where T: Read, { #[inline] fn read(bytes: &[u8], pos: &mut usize) -> Result<Self, ReadError> { if bytes.len() - *pos > 0 { T::read(bytes, pos).map(|t| Self(Some(t))) } else { Ok(Self(None)) } } } impl<T> Write for BinaryExtension<T> where T: Write, { #[inline] fn write( &self, bytes: &mut [u8], pos: &mut usize, ) -> Result<(), WriteError> { match &self.0 { Some(t) => t.write(bytes, pos), None => Ok(()), } } } impl<T> BinaryExtension<T> { #[inline] pub const fn new(t: Option<T>) -> Self { Self(t) } #[inline] pub fn as_value(&self) -> Option<&T> { self.0.as_ref() } #[allow(clippy::missing_const_for_fn)] #[inline] pub fn into_value(self) -> Option<T> { self.0 } }