bevy_reflect: Disambiguate type bounds in where clauses. #8761
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alice-i-cecile
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alice-i-cecile
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How would I go about doing that? I've never made tests for proc-macro output before. EDIT: Question answered on Discord
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alice-i-cecile
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Jun 5, 2023
It was accidentally found that rustc is unable to parse certain
constructs in `where` clauses properly. bevy_reflect::Reflect's habit
of copying and pasting the types in a struct's definition to its where
clauses made it very easy to accidentally run into this behaviour -
particularly with the construct
for<'a> fn(&'a T) -> &'a T: Trait1 + Trait2
which was incorrectly parsed as
for<'a> (fn(&'a T) -> &'a T: Trait1 + Trait2)
instead of
(for<'a> fn(&'a T) -> &'a T): Trait1 + Trait2
This commit fixes the issue by inserting explicit parentheses to
disambiguate types from their bound lists.
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Fixed a merge conflict that occurred due to unfortunate timing between my PR and another one. |
alice-i-cecile
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Jun 5, 2023
MrGVSV
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Objective
It was accidentally found that rustc is unable to parse certain constructs in
whereclauses properly.bevy_reflect::Reflect's habit of copying and pasting the field types in a type's definition to itswhereclauses made it very easy to accidentally run into this behaviour - particularly with the constructwhere for<'a> fn(&'a T) -> &'a T: Trait1 + Trait2which was incorrectly parsed as
where for<'a> (fn(&'a T) -> &'a T: Trait1 + Trait2) ^ ^ incorrect syntax groupinginstead of
where (for<'a> fn(&'a T) -> &'a T): Trait1 + Trait2 ^ ^ correct syntax groupingFixes #8759
Solution
This commit fixes the issue by inserting explicit parentheses to disambiguate types from their bound lists.