Fix documentation example for transparent error pattern#444
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veeceey wants to merge 1 commit intodtolnay:masterfrom
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Fix documentation example for transparent error pattern#444veeceey wants to merge 1 commit intodtolnay:masterfrom
veeceey wants to merge 1 commit intodtolnay:masterfrom
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The example showing how to use #[error(transparent)] with #[from] on a struct wrapping an enum had a placeholder (...) that didn't compile when users tried to complete it. Added a concrete example showing: - A variant in ErrorRepr with #[from] attribute - Helper code demonstrating the From trait chain works correctly - A working example function that uses the ? operator The key insight is that functions need to return Result<(), ErrorRepr> for the From chain to work: InvalidInputError -> ErrorRepr -> PublicError Fixes dtolnay#439
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The documentation example showing how to use
#[error(transparent)]with#[from]on a struct wrapping an enum had a placeholder (...) that caused compilation errors when users tried to complete it.Changes
#[from]Fromtrait chain works correctly?operatorKey Detail
The important pattern shown is that intermediate functions should return
Result<(), ErrorRepr>so the conversion chain works:InvalidInputError→ErrorRepr→PublicErrorTesting
Fixes #439