mirror of https://github.com/rust-lang/rust
22 lines
478 B
Rust
22 lines
478 B
Rust
#![feature(box_patterns)]
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#![allow(dead_code)]
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#![allow(unused_variables)]
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#![deny(unreachable_patterns)]
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enum IntList {
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Cons(isize, Box<IntList>),
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Nil
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}
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fn tail(source_list: &IntList) -> IntList {
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match source_list {
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&IntList::Cons(val, box ref next_list) => tail(next_list),
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&IntList::Cons(val, box IntList::Nil) => IntList::Cons(val, Box::new(IntList::Nil)),
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//~^ ERROR unreachable pattern
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_ => panic!(),
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}
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}
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fn main() {}
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