cpp-coding-standards

# C++ Coding Standards (C++ Core Guidelines) Comprehensive coding standards for modern C++ (C++17/20/23) derived from the [C++ Core Guidelines](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines). Enforces type safety, resource safety, immutability, and clarity. ## When to Use - Writing new C++ code (classes, functions, templates) - Reviewing or refactoring existing C++ code - Making architectural decisions in C++ projects - Enforcing consistent style across a C++ codebase - Choosing between language features (e.g., `enum` vs `enum class`, raw pointer vs smart pointer) ### When NOT to Use - Non-C++ projects - Legacy C codebases that cannot adopt modern C++ features - Embedded/bare-metal contexts where specific guidelines conflict with hardware constraints (adapt selectively) ## Cross-Cutting Principles These themes recur across the entire guidelines and form the foundation: 1. **RAII everywhere** (P.8, R.1, E.6, CP.20): Bind resource lifetime to object lifetime 2. **Immutability by default** (P.10, Con.1-5, ES.25): Start with `const`/`constexpr`; mutability is the exception 3. **Type safety** (P.4, I.4, ES.46-49, Enum.3): Use the type system to prevent errors at compile time 4. **Express intent** (P.3, F.1, NL.1-2, T.10): Names, types, and concepts should communicate purpose 5. **Minimize complexity** (F.2-3, ES.5, Per.4-5): Simple code is correct code 6. **Value semantics over pointer semantics** (C.10, R.3-5, F.20, CP.31): Prefer returning by value and sco...