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deduplicate Tag enum

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cyrgani 2026-02-06 13:52:21 +00:00
parent a6062a84bc
commit 74d2616efc
1 changed files with 25 additions and 33 deletions
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58
library/proc_macro/src/bridge/rpc.rs
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@ -52,45 +52,37 @@ macro_rules! rpc_encode_decode {
}
};
(enum $name:ident $(<$($T:ident),+>)? { $($variant:ident $(($field:ident))*),* $(,)? }) => {
impl<S, $($($T: Encode<S>),+)?> Encode<S> for $name $(<$($T),+>)? {
fn encode(self, w: &mut Buffer, s: &mut S) {
// HACK(eddyb): `Tag` enum duplicated between the
// two impls as there's no other place to stash it.
#[allow(non_camel_case_types)]
#[repr(u8)]
enum Tag { $($variant),* }
#[allow(non_upper_case_globals, non_camel_case_types)]
const _: () = {
#[repr(u8)] enum Tag { $($variant),* }
match self {
$($name::$variant $(($field))* => {
(Tag::$variant as u8).encode(w, s);
$($field.encode(w, s);)*
})*
$(const $variant: u8 = Tag::$variant as u8;)*
impl<S, $($($T: Encode<S>),+)?> Encode<S> for $name $(<$($T),+>)? {
fn encode(self, w: &mut Buffer, s: &mut S) {
match self {
$($name::$variant $(($field))* => {
$variant.encode(w, s);
$($field.encode(w, s);)*
})*
}
}
}
}
impl<'a, S, $($($T: for<'s> Decode<'a, 's, S>),+)?> Decode<'a, '_, S>
for $name $(<$($T),+>)?
{
fn decode(r: &mut &'a [u8], s: &mut S) -> Self {
// HACK(eddyb): `Tag` enum duplicated between the
// two impls as there's no other place to stash it.
#[allow(non_upper_case_globals, non_camel_case_types)]
mod tag {
#[repr(u8)] enum Tag { $($variant),* }
$(pub(crate) const $variant: u8 = Tag::$variant as u8;)*
}
match u8::decode(r, s) {
$(tag::$variant => {
$(let $field = Decode::decode(r, s);)*
$name::$variant $(($field))*
})*
_ => unreachable!(),
impl<'a, S, $($($T: for<'s> Decode<'a, 's, S>),+)?> Decode<'a, '_, S>
for $name $(<$($T),+>)?
{
fn decode(r: &mut &'a [u8], s: &mut S) -> Self {
match u8::decode(r, s) {
$($variant => {
$(let $field = Decode::decode(r, s);)*
$name::$variant $(($field))*
})*
_ => unreachable!(),
}
}
}
}
};
}
}