add track_caller attribute to map_err and ok_or/_else #142093
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Relevant previous discussion: #91752 |
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add track_caller attribute to map_err and ok_or/_else
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Motivation unicode-org/icu4x#4048
This PR resolves a common edge case where users attempting to manually track `std::panic::Location`s of their callers in their `Error` types end up with irrelevant locations inside of `std`.
The main concern with this approach that I'm aware of is that `#[track_caller]` increases the stack sizes of the functions it is applied to, though I think this is a non-issue since we already have `#[track_caller]` on `Result`'s `FromResidual` impl which is used far more frequently than any of these APIs when converting errors between different types. This change brings these functions in line with that impl.
example demonstrating the issue: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=8205bcd02b380d9fd02b1f1153ac9c4e
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Motivation unicode-org/icu4x#4048
This PR resolves a common edge case where users attempting to manually track
std::panic::Locations of their callers in theirErrortypes end up with irrelevant locations inside ofstd.The main concern with this approach that I'm aware of is that
#[track_caller]increases the stack sizes of the functions it is applied to, though I think this is a non-issue since we already have#[track_caller]onResult'sFromResidualimpl which is used far more frequently than any of these APIs when converting errors between different types. This change brings these functions in line with that impl.example demonstrating the issue: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=8205bcd02b380d9fd02b1f1153ac9c4e