mirror of https://github.com/rust-lang/rust
28 lines
732 B
Rust
28 lines
732 B
Rust
// We should not see the unused_attributes lint fire for
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// rustc_on_unimplemented, but with this bug we are seeing it fire (on
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// subsequent runs) if incremental compilation is enabled.
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//@ revisions: cfail1 cfail2
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//@ build-pass (FIXME(62277): could be check-pass?)
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#![feature(rustc_attrs)]
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#![deny(unused_attributes)]
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#[rustc_on_unimplemented = "invalid"]
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trait Index<Idx: ?Sized> {
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type Output: ?Sized;
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fn index(&self, index: Idx) -> &Self::Output;
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}
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#[rustc_on_unimplemented = "a usize is required to index into a slice"]
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impl Index<usize> for [i32] {
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type Output = i32;
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fn index(&self, index: usize) -> &i32 {
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&self[index]
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}
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}
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fn main() {
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Index::<usize>::index(&[1, 2, 3] as &[i32], 2);
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}
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