cpp

proof/cpp — C++ stack working example

End-to-end demo that the C++ capture+validate stack is functional.

What's here

proof/cpp/
├── README.md                    ← this file
├── demo_math.cpp                ← pure C++ functions: free functions + MathUtils class
├── demo_math.hpp                ← header
├── regret_adapter.cpp           ← JSON-in/JSON-out adapter for each cluster
├── verify-parity.mjs            ← cross-stack fingerprint parity check (C++ hash == JS hash)
├── demo-refactor-flow.sh        ← end-to-end PASS/FAIL demo script
└── regrets/
    ├── manifest.json            ← 8 C++ clusters
    ├── add.regret               ← captured contract
    ├── fibonacci.regret
    ├── reverse.regret
    ├── parse-csv-line.regret
    ├── format-bytes.regret
    ├── factorial.regret         ← class-method example
    ├── gcd.regret               ← class-method, multi-arg
    └── is-palindrome.regret     ← class-method, returns bool

Running the demo

# 1. Capture (writes/regenerates all 8 .regret files)
CPP_SOURCES="$(pwd)/demo_math.cpp:$(pwd)/regret_adapter.cpp" \
    CPP_INCLUDE="$(pwd)" \
    bash ../../scripts/capture_cpp.sh

# 2. Validate (should PASS — code unchanged since capture)
CPP_SOURCES="$(pwd)/demo_math.cpp:$(pwd)/regret_adapter.cpp" \
    CPP_INCLUDE="$(pwd)" \
    bash ../../scripts/validate_cpp.sh

# 3. Cross-stack parity check (C++ hash == JS hash)
node ../verify-parity.mjs

# 4. End-to-end refactor flow (valid refactor PASSes, breaking FAILs, exception safety)
bash demo-refactor-flow.sh

Verified contract

• ✅ capture writes .regret files with the standard format (cluster/version/fingerprint/captured/INPUT/OUTPUT/HASH)
• ✅ validate PASSes when the captured code is unchanged
• ✅ validate PASSes for a valid refactor that preserves output (iterative → Binet's formula for fibonacci)
• ✅ validate FAILs (non-zero exit) for a breaking refactor that changes output (off-by-one in fibonacci: 55 → 89)
• ✅ C++ exception safety: when an adapter throws a C++ exception during validate, the harness catches it and reports the cluster as FAIL (no crash) — other clusters still validate normally
• ✅ Class-method support: adapters can instantiate C++ classes and call instance methods (factorial, gcd, is_palindrome)
• ✅ C++ fingerprint is byte-identical to JS fingerprint() for the same (input, output) pair — verified by verify-parity.mjs
• ✅ C++ fingerprint is also byte-identical to the C and Java stacks' fingerprints for the 5 shared free-function clusters (13mxb0z / 587q30m / 1ky49hx / 8xifg6f / 4zbjvg6)