C++ Coding Standards

When reviewing or generating C++ code, follow these rules:

File Naming

• Source files: snake_case or PascalCase with .cpp extension (e.g., user_service.cpp or UserService.cpp )

• Header files: Same base name with .h , .hpp , or .hxx extension

• Template files: .tpp or .inl for template implementations

• Be consistent within a project

Header Guards / Pragma

• Prefer #pragma once for modern compilers

• Or use traditional guards: UPPER_SNAKE_CASE with _HPP suffix

#pragma once // or #ifndef USER_SERVICE_HPP #define USER_SERVICE_HPP #endif

Namespace Naming

• Namespaces: all_lowercase or snake_case (e.g., myproject , data_processing )

• Nested namespaces: Use C++17 syntax when possible (e.g., namespace project::utils {} )

• Avoid using namespace in headers

Variable Naming

• Local variables: snake_case or camelCase (e.g., user_count or userCount )

• Member variables: Prefix with m_ or suffix with _ (e.g., m_data or data_ )

• Static members: Prefix with s_ (e.g., s_instance )

• Constants: UPPER_SNAKE_CASE or kPascalCase (e.g., MAX_SIZE or kMaxSize )

• Global variables: Prefix with g_ (e.g., g_config )

Function/Method Naming

• Free functions: snake_case or camelCase (e.g., calculate_total() or calculateTotal() )

• Member functions: camelCase or PascalCase (e.g., getUserId() or GetUserId() )

• Getters/Setters: get /set prefix or just property name (e.g., getName() or name() )

• Factory functions: Create , Make , or Build prefix (e.g., CreateUser() )

Class/Type Naming

• Classes: PascalCase (e.g., UserService , DataProcessor )

• Structs: PascalCase (e.g., Point , Rectangle )

• Interfaces: PascalCase with I prefix optional (e.g., ISerializable or Serializable )

• Template parameters: Single letter or PascalCase (e.g., T , Container , KeyType )

• Enums: PascalCase for type, UPPER_SNAKE_CASE or PascalCase for values

• Type aliases: PascalCase (e.g., using StringList = std::vector<std::string>; )

Smart Pointers

• Use std::unique_ptr for single ownership

• Use std::shared_ptr for shared ownership

• Avoid raw new /delete

Organization

• Include guards / pragma once

• System includes (alphabetical)

• Project includes (alphabetical)

• Forward declarations

• Namespace opening

• Class declarations

• Inline/template implementations