41 lines
1.2 KiB
Rust
41 lines
1.2 KiB
Rust
use std::{any, marker::PhantomData};
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use type_fn::*;
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pub struct EmptyList;
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pub struct ListExt<T, Next>(PhantomData<T>, PhantomData<Next>);
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pub struct RemovalResult<Element, List>(PhantomData<Element>, PhantomData<List>);
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type_fn! {
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pub fn AddElement<List, Element>;
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pub fn RemoveLastElement<List>;
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pub fn GetRemoved<R>;
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pub fn GetChangedList<R>;
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}
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type_fn_impl! {
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fn<TypeFn> AddElement<List, Element> => ListExt<Element, List>;
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fn<TypeFn> RemoveLastElement<List => ListExt<Element, List> | Element> => RemovalResult<Element, List>;
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fn<TypeFn> GetRemoved<Element => RemovalResult<Element, List> | List> => Element;
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fn<TypeFn> GetChangedList<List => RemovalResult<Element, List> | Element> => List;
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}
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fn main() {
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struct Hello;
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struct World;
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type MyListA = EmptyList;
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type MyListB = call!(AddElement<MyListA, World>);
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type MyListC = call!(AddElement<MyListB, Hello>);
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type RemovalA = call!(RemoveLastElement<MyListC>);
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println!("{}", any::type_name::<call!(GetRemoved<RemovalA>)>());
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type MyListD = call!(GetChangedList<RemovalA>);
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type RemovalB = call!(RemoveLastElement<MyListD>);
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println!("{}", any::type_name::<call!(GetRemoved<RemovalB>)>());
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}
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