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use disjoint_impls::disjoint_impls;
use remote_trait::ForeignKita;
pub trait Dispatch {
type Group;
}
pub enum GroupA {}
impl Dispatch for String {
type Group = GroupA;
}
impl<T> Dispatch for Vec<T> {
type Group = GroupA;
}
pub enum GroupB {}
impl Dispatch for i32 {
type Group = GroupB;
}
impl Dispatch for u32 {
type Group = GroupB;
}
struct LocalType<T>(T);
disjoint_impls! {
#[disjoint_impls(remote)]
pub trait ForeignKita<U> {
fn kita() -> &'static str {
unreachable!("read from the original")
}
}
impl<U, T: Dispatch<Group = GroupA>> ForeignKita<U> for LocalType<T> {
fn kita() -> &'static str {
"Blanket A"
}
}
impl<U, T: Dispatch<Group = GroupB>> ForeignKita<U> for LocalType<T> {
fn kita() -> &'static str {
"Blanket B"
}
}
}
/*
const _: () = {
pub trait ForeignKita0<
_TŠČ1: ?core::marker::Sized,
_TŠČ0,
>: ForeignKita<_TŠČ0> {
fn kita_šč() -> &'static str {
unreachable!("read from the original")
}
}
impl<U, T: Dispatch<Group = GroupA>> ForeignKita0<GroupA, U> for LocalType<T> {
fn kita_šč() -> &'static str {
"Blanket A"
}
}
impl<U, T: Dispatch<Group = GroupB>> ForeignKita0<GroupB, U> for LocalType<T> {
fn kita_šč() -> &'static str {
"Blanket B"
}
}
impl<_TŠČ0, _TŠČ1> ForeignKita<_TŠČ0> for LocalType<_TŠČ1>
where
_TŠČ1: Dispatch,
Self: for<'_dšč> ForeignKita0<<_TŠČ1 as Dispatch>::Group, _TŠČ0>,
{
fn kita() -> &'static str {
<Self as ForeignKita0<<_TŠČ1 as Dispatch>::Group, _TŠČ0>>::kita_šč()
}
}
};
*/
#[test]
fn remote_trait() {
assert_eq!("Blanket A", <LocalType<String> as ForeignKita<u8>>::kita());
assert_eq!(
"Blanket A",
<LocalType<Vec::<u32>> as ForeignKita<u16>>::kita()
);
assert_eq!("Blanket B", <LocalType<u32> as ForeignKita<u32>>::kita());
assert_eq!("Blanket B", <LocalType<i32> as ForeignKita<u64>>::kita());
}