Define checked conversion and bounds-safe indexing policy #39

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1. mgradwohl commented on Feb 27, 2023

   

   mgradwohl

   on Feb 27, 2023

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   If wil has an equivalent to gsl::at this would reduce the dependencies.

   https://github.com/microsoft/wil/wiki/safe_cast
   and
   https://github.com/Microsoft/wil/blob/master/include/wil/safecast.h
2. mgradwohl

   changed the title [-]investigate wil::safe_cast vs gsl::narrow_cast[/-] [+]investigate wil::safe_cast vs gsl::narrow_cast and wil equivalent of gsl::at[/+] on Feb 27, 2023
3. mgradwohl commented on Nov 9, 2026

   

   mgradwohl

   on Nov 9, 2026 – with Copilot SWE Agent

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   Backlog triage

   Status: Still open.
   Severity: low. Priority: med. Impact: maintenance.
   Assessed against fdf20b4cbfbbb8009d45296f3d60f0f541ee539b.

   Evidence

   Shape.cpp:70-91 still narrows dimensions before validation; Renderer.cpp:84-89 narrows hit-test coordinates; Board.h:50-63 relies on flattened vector::at. No documented choice of checked conversion/indexing policy is present.

   Disposition and remaining scope

   The investigation has not been resolved into a safe, consistent policy. gsl::narrow_cast is intentionally unchecked, and vector::at does not validate two-dimensional coordinates. Keep this as a cross-cutting design task; the concrete crash/corruption fixes are #16 and #54 and should be fixed first, not hidden behind a mechanical helper replacement.

   Completion criteria

   • Distinguish proven-safe casts from user/file-derived checked conversions.
   • Evaluate the actual failure semantics of any WIL/GSL helper before adopting it.
   • Validate arithmetic and ranges before narrowing, and validate both grid axes before flattening.
   • Document the chosen exception/result/fail-fast policy and add boundary tests; avoid renaming casts without adding checks.
4. mgradwohl

   changed the title [-]investigate wil::safe_cast vs gsl::narrow_cast and wil equivalent of gsl::at[/-] [+]Define checked conversion and bounds-safe indexing policy[/+] on Nov 9, 2026
5. mgradwohl

   added

   enhancementNew feature or requestNew feature or request

   severity: lowLimited impact, maintenance improvement, or optional new capabilityLimited impact, maintenance improvement, or optional new capability

   priority: medFix next: reliability, maintainability, and high-value usabilityFix next: reliability, maintainability, and high-value usability

   impact: maintenanceReview impact category: maintenanceReview impact category: maintenance

   on Nov 9, 2026