Macro uninit::read::auto_impl

pub macro auto_impl(#[derived_from(ReadIntoUninit)] impl $([$($generics : tt) *]) ? Read for $T :
 ty $(where $($where_clause : tt) *) ?) {
    ...
}

This is supported on crate feature std only.

Helper macro to alleviate the code duplication from implementing both Read and ReadIntoUninit.

Once some type T implements ReadIntoUninit, you can derive Read by doing:

::uninit::read::auto_impl! {
    #[derived_from(ReadIntoUninit)]
    impl Read for X
}
// and if X is generic, over, for instance, `Generics`
::uninit::read::auto_impl! {
    #[derived_from(ReadIntoUninit)]
    impl[Generics] Read for X<Generics>
}