C++ Code Review Patterns

Overview

C++ combines the expressive power of high-level abstractions with direct control over hardware resources — and pays for it with a class of bugs that no compiler or runtime can fully prevent. A reviewer trained on Java, Python, or even Rust will miss the failure modes that are unique to C++: resource leaks that appear only under exceptions, undefined behavior that silently produces wrong results in optimized builds, template errors that require a compiler archaeology dig to interpret, and move semantics that invalidate objects in ways that look valid at a glance.

This guide covers six areas where C++ code most commonly fails in review or in production: memory management and RAII, undefined behavior, template pitfalls, const correctness, move semantics, and systemic anti-patterns. Each section includes before/after code examples and severity rules calibrated to real-world impact.

Load this skill when reviewing any C++ PR that touches resource acquisition, performance-critical hot paths, public APIs, or code that must be exception-safe. Cross-reference review-accuracy-calibration before posting: many C++ issues are compiler-detectable with the right flags (-Wall -Wextra -fsanitize=address,undefined), and findings backed by sanitizer evidence are C4; findings based on code reading alone are typically C3.

Quick Reference