33 lines
647 B
Rust
33 lines
647 B
Rust
trait ATC<'a> {
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type Type: Sized;
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}
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trait WithDefault: for<'a> ATC<'a> {
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fn with_default<F: for<'a> Fn(<Self as ATC<'a>>::Type)>(f: F);
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}
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fn call<'b, T: for<'a> ATC<'a>, F: for<'a> Fn(<T as ATC<'a>>::Type)>(
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f: F,
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x: <T as ATC<'b>>::Type,
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) {
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f(x);
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}
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impl<'a> ATC<'a> for () {
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type Type = Self;
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}
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impl WithDefault for () {
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fn with_default<F: for<'a> Fn(<Self as ATC<'a>>::Type)>(f: F) {
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// Errors with a bogus type mismatch.
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//f(());
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// Going through another generic function works fine.
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call(f, ());
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//~^ expected a
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}
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}
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fn main() {
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// <()>::with_default(|_| {});
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}
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