ECC is a toolkit that organizes and improves how coding agents work through skills, memory, security checks, research practices, and related extensions. It is for developers using agents such as Claude Code, Codex, OpenCode, and Cursor.
Borrowing it
Nothing to install: this file belongs to affaan-m/ECC. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/affaan-m/ECC/main/.kiro/steering/cpp-patterns.mdgit clone --depth 1 https://github.com/affaan-m/ECCWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/affaan-m/ecc/cpp-patterns)<a href="https://agentmods.dev/instructions/affaan-m/ecc/cpp-patterns"><img src="https://agentmods.dev/badge/instructions/affaan-m/ecc/cpp-patterns.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00723 | $0.00723 |
| Opus 5 | $0.00362 | $0.00362 |
| Sonnet 5 | $0.00145 | $0.00145 |
| Haiku 4.5 | $0.00072 | $0.00072 |
Grade A, and why
ECC cpp-patterns.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C++ Patterns
This file extends the common patterns with C++ specific content.
Modern C++ (C++17/20/23)
- Prefer modern C++ features over C-style constructs
- Use
autowhen the type is obvious from context - Use
constexprfor compile-time constants - Use structured bindings:
auto [key, value] = map_entry;
RAII (Resource Acquisition Is Initialization)
Tie resource lifetime to object lifetime — no manual new/delete:
class FileHandle {
public:
explicit FileHandle(const std::string& path) : file_(std::fopen(path.c_str(), "r")) {}
~FileHandle() { if (file_) std::fclose(file_); }
FileHandle(const FileHandle&) = delete;
FileHandle& operator=(const FileHandle&) = delete;
private:
std::FILE* file_;
};
Smart Pointers
- Use
std::unique_ptrfor exclusive ownership - Use
std::shared_ptronly when shared ownership is truly needed - Use
std::make_unique/std::make_sharedover rawnew
Rule of Five/Zero
- Rule of Zero: Prefer classes that need no custom destructor, copy/move constructors, or assignments
- Rule of Five: If you define any of destructor/copy-ctor/copy-assign/move-ctor/move-assign, define all five
Value Semantics & Error Handling
- Pass small/trivial types by value, large types by
const& - Return by value (rely on RVO/NRVO)
- Use
std::optionalfor values that may not exist - Use
std::expected(C++23) or result types for expected failures
Memory Safety
- Never use raw
new/delete— use smart pointers - Never use C-style arrays — use
std::arrayorstd::vector - Use
std::stringoverchar* - Use
.at()for bounds-checked access when safety matters - Never use
strcpy,strcat,sprintf
Formatting & Static Analysis
clang-format -i <file>
clang-tidy --checks='*' src/*.cpp
cppcheck --enable=all src/
Testing
Use GoogleTest (gtest/gmock) with CMake/CTest:
cmake --build build && ctest --test-dir build --output-on-failure
Always run tests with sanitizers in CI:
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- today First seen · 93 lines · 723 tokens per session scan A c3739794b920
ECC cpp-patterns.md is an instructions file published in the GitHub repository affaan-m/ECC (251,781 stars, last pushed today), licensed MIT. It adds 723 tokens to every session, about $0.0036 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-07.
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