# C++ Code Review

Review {{input}} for correctness, modern style, and best practices.

## Resource Management (RAII)
- Own resources through RAII types; avoid raw `new`/`delete`
- Use `std::unique_ptr` for exclusive ownership, `std::shared_ptr` only when shared ownership is genuinely needed
- Prefer stack allocation and value semantics over heap allocation
- Rule of Five: if you define any of destructor, copy constructor, copy assignment, move constructor, move assignment — define all five (or `= delete` / `= default` explicitly)

## Correctness
- Avoid undefined behaviour: no signed overflow, no out-of-bounds, no null dereference, no use-after-free
- Mark functions `noexcept` only when they genuinely cannot throw; broken `noexcept` contracts call `terminate()`
- Use `std::optional`, `std::variant`, or exceptions for error states — never sentinel values like `-1` for sizes
- Avoid `reinterpret_cast`; prefer `static_cast` with explicit validation

## Modern C++ (C++17/20)
- Prefer range-based for loops and standard algorithms over raw index loops
- Use structured bindings and `if`-initializers where they improve clarity
- Prefer `std::string_view` over `const std::string&` for non-owning string parameters
- Replace C-style arrays with `std::array` or `std::vector`

## Concurrency (if applicable)
- Protect shared mutable state with `std::mutex`; use `std::lock_guard`/`std::unique_lock`
- No data races — review all shared state accessed from multiple threads
- Prefer `std::atomic` for simple flags and counters over a mutex

## Code Quality
- Compile with `-Wall -Wextra -Wpedantic` and enable sanitizers (`-fsanitize=address,undefined`)
- Mark member functions `const` when they do not modify state
- No raw owning pointers in public APIs; no C-style casts

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List findings as **Critical** (UB/memory unsafety/data races) -> **Major** (bugs/resource leaks/wrong semantics) -> **Minor** (style/modern idioms). Cite each location and suggest the concrete fix.