Macro mpeg2ts_reader::descriptor_enum

macro_rules! descriptor_enum {
    (
        $(#[$outer:meta])*
        $name:ident {
            $(
                $(#[$inner:ident $($args:tt)*])*
                $case_name:ident $($tags:pat)|* => $t:ident
            ),*,
        }
    ) => { ... };
}

Builds an enum to encapsulate all possible implementations of Descriptor that you want to be able to handle in your application.

The list of variants is supplied in the macro body together with the ‘tag’ values of each option. The macro will generate an implementation of descriptor::Descriptor whose from_bytes() function will return the variant for the tag value found within the input buffer.

use mpeg2ts_reader::descriptor::*;

struct MySpecialDescriptor<'buf> {
    // ...
};
impl<'buf> MySpecialDescriptor<'buf> {
    pub fn new(tag: u8, payload: &'buf [u8]) -> Result<Self, DescriptorError> {
        // ...
    }
}

descriptor_enum! {
    // you could #[derive(Debug)] here if you wanted
    MyOwnDescriptors {
        /// descriptor tag values `0`, `1` and `57` to `62` inclusive are marked as reserved
        /// by _ISO/IEC 13818-1_.  If any of these tag values are found,
        /// MyOwnDescriptors::from_bytes() will return MyOwnDescriptors::Reserved.
        Reserved 0|1|57..=62 => UnknownDescriptor,
        Other 2..=56|63..=254 => UnknownDescriptor,
        /// When MyOwnDescriptors::from_bytes() finds the value 255, it will return the
        /// MyOwnDescriptors::MySpecialPrivate variant, which will in turn wrap an instance
        /// of MySpecialDescriptor.
        MySpecialPrivate 255 => MySpecialDescriptor,
    }
}