C++ Development

Write safe, performant modern C++ code.

When to Use

• Writing C++ code

• Memory management issues

• Template metaprogramming

• Performance optimization

• Legacy C++ modernization

Modern C++ Patterns

Smart Pointers

// Unique ownership auto ptr = std::make_unique<Resource>(); process(std::move(ptr));

// Shared ownership auto shared = std::make_shared<Resource>(); auto copy = shared; // Reference count: 2

// Weak reference (no ownership) std::weak_ptr<Resource> weak = shared; if (auto locked = weak.lock()) { // Use locked }

RAII

class FileHandle { FILE* handle_; public: explicit FileHandle(const char* path) : handle_(fopen(path, "r")) { if (!handle_) throw std::runtime_error("Failed to open"); } ~FileHandle() { if (handle_) fclose(handle_); }

// Rule of 5
FileHandle(const FileHandle&) = delete;
FileHandle& operator=(const FileHandle&) = delete;
FileHandle(FileHandle&& other) noexcept
    : handle_(std::exchange(other.handle_, nullptr)) {}
FileHandle& operator=(FileHandle&& other) noexcept {
    std::swap(handle_, other.handle_);
    return *this;
}

};

Containers and Algorithms

std::vector<int> nums = {3, 1, 4, 1, 5};

// Prefer algorithms over raw loops std::sort(nums.begin(), nums.end());

auto it = std::find_if(nums.begin(), nums.end(), [](int n) { return n > 3; });

// Range-based for for (const auto& num : nums) { std::cout << num << '\n'; }

// Structured bindings (C++17) std::map<std::string, int> scores; for (const auto& [name, score] : scores) { std::cout << name << ": " << score << '\n'; }

Templates

// Concepts (C++20) template<typename T> concept Numeric = std::integral<T> || std::floating_point<T>;

template<Numeric T> T sum(const std::vector<T>& values) { return std::accumulate(values.begin(), values.end(), T{}); }

// SFINAE (pre-C++20) template<typename T, typename = std::enable_if_t<std::is_arithmetic_v<T>>> T multiply(T a, T b) { return a * b; }

Best Practices

• Prefer const and constexpr

• Use smart pointers over raw pointers

• Follow Rule of 0/5

• Prefer STL algorithms

• Use std::string_view for read-only strings

• Enable warnings: -Wall -Wextra -Wpedantic

Common Issues

Issue Symptom Fix

Memory leak Growing memory Use smart pointers

Dangling ptr Crash/UB Check lifetime

Buffer overflow Crash/security Use std::vector/span

Data race Inconsistent state mutex/atomic

Examples

Input: "Fix memory leak" Action: Replace raw pointers with smart pointers, ensure RAII

Input: "Modernize this C++ code" Action: Apply C++17/20 features, use STL, improve safety