Cpp Skill
C++ Programming Guidelines
Basic Principles
- Use English for all code and documentation.
- Always declare the type of each variable and function (parameters and return value).
- Create necessary types and classes.
- Use Doxygen style comments to document public classes and methods.
- Don't leave blank lines within a function.
- Follow the one-definition rule (ODR).
Nomenclature
- Use PascalCase for classes and structures.
- Use camelCase for variables, functions, and methods.
- Use ALL_CAPS for constants and macros.
- Use snake_case for file and directory names.
- Use UPPERCASE for environment variables.
- Avoid magic numbers and define constants.
- Start each function with a verb.
- Use verbs for boolean variables. Example: isLoading, hasError, canDelete, etc.
- Use complete words instead of abbreviations and ensure correct spelling.
- Except for standard abbreviations like API, URL, etc. - Except for well-known abbreviations: - i, j, k for loops - err for errors - ctx for contexts - req, res for request/response parameters
Functions
- Write short functions with a single purpose. Less than 20 instructions.
- Name functions with a verb and something else.
- If it returns a boolean, use isX or hasX, canX, etc.
- If it doesn't return anything (void), use executeX or saveX, etc.
- Avoid nesting blocks by:
- Early checks and returns. - Extraction to utility functions.
- Use standard library algorithms (std::for_each, std::transform, std::find, etc.) to avoid function nesting.
- Use lambda functions for simple operations.
- Use named functions for non-simple operations.
- Use default parameter values instead of checking for null or nullptr.
- Reduce function parameters using structs or classes
- Use an object to pass multiple parameters. - Use an object to return multiple results. - Declare necessary types for input arguments and output.
- Use a single level of abstraction.
Data
- Don't abuse primitive types and encapsulate data in composite types.
- Avoid data validations in functions and use classes with internal validation.
- Prefer immutability for data.
- Use const for data that doesn't change.
- Use constexpr for compile-time constants.
- Use std::optional for possibly null values.
Classes
- Follow SOLID principles.
- Prefer composition over inheritance.
- Declare interfaces as abstract classes or concepts.
- Write small classes with a single purpose.
- Less than 200 instructions. - Less than 10 public methods. - Less than 10 properties.
- Use the Rule of Five (or Rule of Zero) for resource management.
- Make member variables private and provide getters/setters where necessary.
- Use const-correctness for member functions.
Exceptions
- Use exceptions to handle errors you don't expect.
- If you catch an exception, it should be to:
- Fix an expected problem. - Add context. - Otherwise, use a global handler.
- Use std::optional, std::expected, or error codes for expected failures.
Memory Management
- Prefer smart pointers (std::unique_ptr, std::shared_ptr) over raw pointers.
- Use RAII (Resource Acquisition Is Initialization) principles.
- Avoid memory leaks by proper resource management.
- Use std::vector and other standard containers instead of C-style arrays.
Testing
- Follow the Arrange-Act-Assert convention for tests.
- Name test variables clearly.
- Follow the convention: inputX, mockX, actualX, expectedX, etc.
- Write unit tests for each public function.
- Use test doubles to simulate dependencies.
- Except for third-party dependencies that are not expensive to execute.
- Write integration tests for each module.
- Follow the Given-When-Then convention.
Project Structure
- Use modular architecture
- Organize code into logical directories:
- include/ for header files - src/ for source files - test/ for test files - lib/ for libraries - doc/ for documentation
- Use CMake or similar build system.
- Separate interface (.h) from implementation (.cpp).
- Use namespaces to organize code logically.
- Create a core namespace for foundational components.
- Create a utils namespace for utility functions.
Standard Library
- Use the C++ Standard Library whenever possible.
- Prefer std::string over C-style strings.
- Use std::vector, std::map, std::unordered_map, etc. for collections.
- Use std::optional, std::variant, std::any for modern type safety.
- Use std::filesystem for file operations.
- Use std::chrono for time-related operations.
Concurrency
- Use std::thread, std::mutex, std::lock_guard for thread safety.
- Prefer task-based parallelism over thread-based parallelism.
- Use std::atomic for atomic operations.
- Avoid data races by proper synchronization.
- Use thread-safe data structures when necessary.
Memory Protocol (MANDATORY)
Before starting:
cat .claude/context/memory/learnings.mdAfter completing: Record any new patterns or exceptions discovered.
ASSUME INTERRUPTION: Your context may reset. If it's not in memory, it didn't happen.