Task: Record scope-exit mechanism details

TASK-DESCRIPTION

• Create: documents/24-scope-exit-mechanisms.md
• Modify: scope-exit-mechanisms-report.md

Create documents/24-scope-exit-mechanisms.md. Place the scope-exit mechanism reference in documents/, where human-consumption documents belong, instead of the repository root. The content records the finer clause-level detail for the four non-C++ scope-exit mechanisms: ISO C defer (ISO/IEC TS 25755, draft N3734), the __attribute__((cleanup(fn))) attribute, Objective-C ARC, and Cforall. Record its provenance as a research artifact and its relationship to documents/23-constructor-destructor-variants.md, which summarizes the same mechanisms and is authoritative where the two disagree. Preserve the confidence and unverified list. Do not modify any other file; this task relocates and annotates only documents/24-scope-exit-mechanisms.md.

TASK-OUTPUT

Provide only the complete content of documents/24-scope-exit-mechanisms.md. No commentary.

TASK-CONTEXT

The repository structure permits no root-level files other than README.md (see prompts/01-contract.md §7), and research documents belong in documents/ (see prompts/03-conventions.md §2). The design context is the admissibility boundary in documents/22-fork-or-extend-decision.md §7 and the per-site rulings in documents/23-constructor-destructor-variants.md. The defer mechanism matters to this project because TS 25755 makes it a statement bound to the innermost block, with jumps into or out of it constrained, so it registers only a call the programmer wrote.

TASK-FILES

TASK-VERIFY

• Run: make test from the repository root.
• Expected: exit status 0.

OUTPUT: the content of documents/24-scope-exit-mechanisms.md, as TASK-OUTPUT describes, and nothing else.