Correctly handle bracketed type in default_constructed_unit_struct
#14367
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An expression such as `<_>::default()` should not be replaced by an ambiguous type name such as `_` even if the inferred type in the original expression is a singleton.
This is more consistent with what other lints are doing: the use of `default` to create a unit struct is the whole expression.
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| { | ||
| span_lint_and_sugg( | ||
| let mut removals = vec![(expr.span.with_lo(qpath.qself_span().hi()), String::new())]; | ||
| if expr.span.with_source_text(cx, |s| dbg!(s).starts_with('<')) == Some(true) { |
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Looks like you forgot to remove a dbg here (maybe we should run clippy_lints dogfood with -Dclippy::dbg_macro)
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Thanks for catching this! I've submitted #14579 to avoid this in the future.
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When `<T>::default()` is replaced by `T` when `T` is a singleton, the brackets around the type name can be removed.
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There were two bugs here. Let's assume
Tis a singleton type implementingDefaultand thatf()takes aT:f(<T>::default())cannot be replaced byf(<T)as it was (incorrect spans – this is tricky because the type relative path uses a base span covering onlyT, not<T>) (third commit)f(<_>::default())is inferred correctly, but cannot be replaced by<_>or_, as this cannot be used to infer an instance of a singleton type (first commit).The second commit offers better error messages by pointing at the whole expression.
Fix #12654
changelog: [
default_constructed_unit_struct]: do not suggest incorrect fix when using a type surrounded by brackets