cpp-coding

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.