Trait BitReadSized 

pub trait BitReadSized<E: Endianness>: Sized {
    // Required method
    fn read(stream: &mut BitStream<E>, size: usize) -> Result<Self>;

    // Provided methods
    fn skip(stream: &mut BitStream<E>, size: usize) -> Result<()> { ... }
    fn bit_size_sized(_size: usize) -> Option<usize> { ... }
}

Trait for types that can be read from a stream, requiring the size to be configured

The meaning of the set sized depends on the type being read (e.g, number of bits for integers, number of bytes for strings, number of items for Vec’s, etc)

The BitReadSized trait can be used with #[derive] on structs

The implementation can be derived for a struct as long as every field in the struct implements BitRead or BitReadSized

The struct is read field by field in the order they are defined in, if the size for a field is set stream.read_sized() will be used, otherwise stream_read() will be used.

The size for a field can be set using 4 different methods

• set the size as an integer using the size attribute,
• use a previously defined field as the size using the size attribute
• based on the input size by setting size attribute to "input_size"
• read a set number of bits as an integer, using the resulting value as size using the size_bits attribute

Examples

#[derive(BitReadSized, PartialEq, Debug)]
struct TestStructSized {
    foo: u8,
    #[size = "input_size"]
    string: String,
    #[size = "input_size"]
    int: u8,
}

Enums

The implementation can be derived for an enum as long as every variant of the enum either has no field, or an unnamed field that implements BitRead or BitReadSized

The enum is read by first reading a set number of bits as the discriminant of the enum, then the variant for the read discriminant is read.

For details about setting the input size for fields implementing BitReadSized see the block about size in the Structs section above.

The discriminant for the variants defaults to incrementing by one for every field, starting with 0. You can overwrite the discriminant for a field, which will also change the discriminant for every following field.

Examples

#[derive(BitReadSized)]
#[discriminant_bits = 2]
enum TestUnnamedFieldEnum {
    #[size = 5]
    Foo(i8),
    Bar(bool),
    #[discriminant = 3] // since rust only allows setting the discriminant on field-less enums, you can use an attribute instead
    #[size = "input_size"]
    Asd(u8),
}

Required Methods

fn read(stream: &mut BitStream<E>, size: usize) -> Result<Self>

Read the type from stream

Provided Methods

fn skip(stream: &mut BitStream<E>, size: usize) -> Result<()>

Skip the type

This might be faster than reading it if the size is known beforehand

fn bit_size_sized(_size: usize) -> Option<usize>

The number of bits that will be read or None if the number of bits will change depending on the bit stream

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<E: Endianness> BitReadSized<E> for i8

fn read(stream: &mut BitStream<E>, size: usize) -> Result<i8>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for i16

fn read(stream: &mut BitStream<E>, size: usize) -> Result<i16>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for i32

fn read(stream: &mut BitStream<E>, size: usize) -> Result<i32>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for i64

fn read(stream: &mut BitStream<E>, size: usize) -> Result<i64>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for i128

fn read(stream: &mut BitStream<E>, size: usize) -> Result<i128>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for u8

fn read(stream: &mut BitStream<E>, size: usize) -> Result<u8>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for u16

fn read(stream: &mut BitStream<E>, size: usize) -> Result<u16>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for u32

fn read(stream: &mut BitStream<E>, size: usize) -> Result<u32>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for u64

fn read(stream: &mut BitStream<E>, size: usize) -> Result<u64>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for u128

fn read(stream: &mut BitStream<E>, size: usize) -> Result<u128>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness> BitReadSized<E> for String

fn read(stream: &mut BitStream<E>, size: usize) -> Result<String>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness, K: BitRead<E> + Eq + Hash, T: BitRead<E>> BitReadSized<E> for HashMap<K, T>

Read K and T size times and return as HashMap<K, T>

fn read(stream: &mut BitStream<E>, size: usize) -> Result<Self>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness, T: BitRead<E>> BitReadSized<E> for Vec<T>

Read T size times and return as Vec<T>

fn read(stream: &mut BitStream<E>, size: usize) -> Result<Self>

fn bit_size_sized(size: usize) -> Option<usize>

impl<E: Endianness, T: BitReadSized<E>> BitReadSized<E> for Option<T>

fn read(stream: &mut BitStream<E>, size: usize) -> Result<Self>

Implementors

impl<E: Endianness> BitReadSized<E> for BitStream<E>

impl<T: BitReadSized<E>, E: Endianness> BitReadSized<E> for LazyBitReadSized<T, E>