Derive Macro neli::Header

#[derive(Header)]
{
    // Attributes available to this derive:
    #[neli]
}

Derives the neli Header trait for a struct or enum. Unlike other derive macros in this crate, the Header derive macro does not impose type parameter bounds on type parameters. See the accepted attribute for more information. The reason for this is that the last field is considered to be the payload. Because the payload may be represented by a type parameter, we cannot blindly restrict type parameters or else we impose an artificial restriction of TypeSize on the payload type parameter. This is a problem for the Header trait as the payload may be unsized even if the rest of the header is composed exclusively of statically sized types and are therefore compatible with the TypeSize trait.

Acceptable struct attribute is:

• #[neli(header_bound = "T: MyTrait")] which will generate a trait bound in the impl for the specified type parameter.

While there is no implicit type parameter bound, every type parameter that does not correspond to a payload should have a specified type parameter bound of TypeSize.