22 lines
428 B
Rust
22 lines
428 B
Rust
// run-pass
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pub trait Parser {
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type Input;
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}
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pub struct Iter<P: Parser>(P, P::Input);
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pub struct Map<P, F>(P, F);
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impl<P, F> Parser for Map<P, F> where F: FnMut(P) {
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type Input = u8;
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}
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trait AstId { type Untyped; }
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impl AstId for u32 { type Untyped = u32; }
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fn record_type<Id: AstId>(i: Id::Untyped) -> u8 {
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Iter(Map(i, |_: Id::Untyped| {}), 42).1
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}
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pub fn main() {
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assert_eq!(record_type::<u32>(3), 42);
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}
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