36 lines
663 B
Rust
36 lines
663 B
Rust
// run-pass
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// This is a regression test for something that only came up while
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// attempting to bootstrap librustc_ast; it is adapted from
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// `syntax::ext::tt::generic_extension`.
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pub struct E<'a> {
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pub f: &'a u8,
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}
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impl<'b> E<'b> {
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pub fn m(&self) -> &'b u8 { self.f }
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}
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pub struct P<'c> {
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pub g: &'c u8,
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}
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pub trait M {
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fn n(&self) -> u8;
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}
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impl<'d> M for P<'d> {
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fn n(&self) -> u8 { *self.g }
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}
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fn extension<'e>(x: &'e E<'e>) -> Box<dyn M+'e> {
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loop {
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let p = P { g: x.m() };
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return Box::new(p) as Box<dyn M+'e>;
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}
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}
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fn main() {
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let w = E { f: &10 };
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let o = extension(&w);
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assert_eq!(o.n(), 10);
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}
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