Problem
ComparisonWithOtherLibraries.en.md — the documentation's "Evaluate" entry point — covers only ErrorOr and FluentResults. The dominant real-world alternative (plain exceptions + ASP.NET Core's built-in ProblemDetails/IProblemDetailsService) is addressed only obliquely in two FAQ entries; CSharpFunctionalExtensions appears in one FAQ line; OneOf/LanguageExt (union style), Ardalis.Result (HTTP-mapping style) and DotNext.Result are never mentioned. An evaluator arriving from any of those ecosystems finds no positioning. The page also lacks a performance/allocation row although ErrorOr is struct-based and that is a real selection criterion.
Impact
The audience a reference library must convince — adopters doing due diligence — is the one the page underserves.
Direction
- Add the exceptions+ProblemDetails baseline worked through the same payment scenario, preserving the page's dated, non-ranking, self-critical method.
- Add a short "other families" section/table (union types, functional results, HTTP-mapping results) pointing to the FAQ's existing arguments.
- Add a performance/allocation row once the core benchmark lands (see the core-benchmark item in the audit backlog) — or an honest "unmeasured" cell until then.
- FR twin in lockstep; refresh the review date.
Acceptance criteria
- An evaluator holding any of the named alternatives finds an explicit, honest positioning; the review date reflects the update.
Context
Surfaced by the 2026-07-20 architecture, design & ecosystem audit (doc/handwritten/for-maintainers/audit/2026-07-20-firstclasserrors-architecture-and-design-audit.md, §13.3(f)/§14-HV16; branch claude/firstclasserrors-audit-83gap7).
Problem
ComparisonWithOtherLibraries.en.md— the documentation's "Evaluate" entry point — covers only ErrorOr and FluentResults. The dominant real-world alternative (plain exceptions + ASP.NET Core's built-in ProblemDetails/IProblemDetailsService) is addressed only obliquely in two FAQ entries; CSharpFunctionalExtensions appears in one FAQ line; OneOf/LanguageExt (union style), Ardalis.Result (HTTP-mapping style) and DotNext.Result are never mentioned. An evaluator arriving from any of those ecosystems finds no positioning. The page also lacks a performance/allocation row although ErrorOr is struct-based and that is a real selection criterion.Impact
The audience a reference library must convince — adopters doing due diligence — is the one the page underserves.
Direction
Acceptance criteria
Context
Surfaced by the 2026-07-20 architecture, design & ecosystem audit (
doc/handwritten/for-maintainers/audit/2026-07-20-firstclasserrors-architecture-and-design-audit.md, §13.3(f)/§14-HV16; branchclaude/firstclasserrors-audit-83gap7).