Trait Header 

pub unsafe trait Header:
    Clone
    + Sized
    + PartialEq
    + Eq
    + Debug {
    // Required methods
    fn total_size(&self) -> usize;
    fn set_size(&mut self, total_size: usize);

    // Provided method
    fn payload_len(&self) -> usize { ... }
}

A sized header type for DynSizedStructure.

Note that header refers to the header pattern. Thus, depending on the use case, this is not just a tag header. Instead, it refers to all bytes that are fixed and not part of any optional terminating dynamic [u8] slice in a DynSizedStructure.

The alignment of implementors must be compatible with the requirements for the corresponding structure, which typically is ALIGNMENT.

Safety

Implementors must be #[repr(C)], have no padding bytes or interior mutability, allow every bit pattern, and have an alignment of at most ALIGNMENT. Headers are referenced from raw memory and copied byte-wise.

Required Methods

fn total_size(&self) -> usize

Returns the total size of the structure in bytes, including the fixed header and any dynamic payload.

fn set_size(&mut self, total_size: usize)

Updates the header with the given total_size.

Implementations should either store the size losslessly or panic on overflow. Construction helpers such as new_boxed verify that the size round-trips through the header and panic otherwise.

Provided Methods

fn payload_len(&self) -> usize

Returns the length of the payload, i.e., the bytes that are additional to the header. The value is measured in bytes.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors