mirror of https://github.com/rust-lang/rust
52 lines
1.2 KiB
Rust
52 lines
1.2 KiB
Rust
//@ check-fail
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#![feature(rustc_attrs)]
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trait Parser<'s> {
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type Output;
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fn call(&self, input: &'s str) -> (&'s str, Self::Output);
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}
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impl<'s, F, T> Parser<'s> for F
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where F: Fn(&'s str) -> (&'s str, T) {
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type Output = T;
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fn call(&self, input: &'s str) -> (&'s str, T) {
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self(input)
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}
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}
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fn foo<F1, F2>(
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f1: F1,
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base: &'static str,
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f2: F2
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)
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where
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F1: for<'a> Parser<'a>,
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F2: FnOnce(&<F1 as Parser>::Output) -> bool
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{
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let s: String = base.to_owned();
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let str_ref = s.as_ref();
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let (remaining, produced) = f1.call(str_ref);
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assert!(f2(&produced));
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assert_eq!(remaining.len(), 0);
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}
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struct Wrapper<'a>(&'a str);
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fn main() {
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fn bar<'a>(s: &'a str) -> (&'a str, &'a str) {
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(&s[..1], &s[..])
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}
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fn baz<'a>(s: &'a str) -> (&'a str, Wrapper<'a>) {
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(&s[..1], Wrapper(&s[..]))
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}
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foo(bar, "string", |s| s.len() == 5);
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//~^ ERROR implementation of `FnOnce` is not general enough
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//~| ERROR implementation of `FnOnce` is not general enough
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foo(baz, "string", |s| s.0.len() == 5);
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//~^ ERROR implementation of `FnOnce` is not general enough
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//~| ERROR implementation of `FnOnce` is not general enough
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}
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