Skip update fallback if return type has non-static lifetime #896
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samscott89
changed the title
src/update.rs
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| @@ -494,6 +494,7 @@ fallback_impl! { compact_str::CompactString, } | |||
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| macro_rules! tuple_impl { | |||
| ($($t:ident),*; $($u:ident),*) => { | |||
| #[diagnostic::do_not_recommend] | |||
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This also seemed like a nice quality of life improvement. The error message just lists all the tuple types otherwise.
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Ah, not supported in 1.80 though
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You can bring this back, we bumped the MSRV now (needs a rebase then)
CodSpeed Performance ReportMerging #896 will not alter performanceComparing Summary
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| impl<'ast> syn::visit::Visit<'ast> for HasLifetimeVisitor { | ||
| fn visit_lifetime(&mut self, l: &'ast syn::Lifetime) { | ||
| // We don't consider `'static` to be a lifetime in this context. | ||
| if l.ident != "static" { | ||
| self.has_lifetime = true; | ||
| } | ||
| } | ||
| } |
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This unfortunately breaks down with macro calls in the type, -> foo!() might expand to something introducing an elided lifetime. Likewise a user could use a Foo<'_> but without specifying the <'_> which warns post 2018 edition, but not error.
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Both of those seem like reasonable gaps to me, since it will still fallback to the current behaviour. Although I could see the argument that it might create even more confusing behaviour.
What do you think the best path forward is? I have no problems with closing this PR if it doesn't seem worth it.
I had a return type like
Result<Tracked<'db>, Error>and the error message was complaining about'dbnot being'static. It took me a while to figure out that the'dbwasn't the problem, it was that myErrortype doesn't implementUpdate.Since tracking down where the
'staticbound comes it's fairly obvious why, but for future people this might provide a slightly easier debugging experience.