Summary

• Add C++20 module files for messaging_system as part of the Tier 5 (Application) layer
• This completes the C++20 module migration across all kcenon systems

Changes

• Module files (src/modules/):

  • messaging.cppm - Primary module interface
  • core.cppm - Core messaging (message, queue, bus, broker)
  • patterns.cppm - Messaging patterns (pub/sub, request/reply)
  • task.cppm - Distributed task queue system
  • integration.cppm - Transports, backends, DI

• CMake (CMakeLists.txt):

  • Add MESSAGING_BUILD_MODULES option (OFF by default)
  • Add messaging_system_modules target with module file set
  • Link dependent module targets (common, thread, container, logger, database, network)

• Documentation:

  • Add C++20 module build section to README.md
  • Add module support entry to CHANGELOG.md

Module Structure

import kcenon.messaging;

// Available partitions:
// - kcenon.messaging:core
// - kcenon.messaging:patterns
// - kcenon.messaging:task
// - kcenon.messaging:integration

Requirements

• CMake 3.28+
• Ninja or Ninja Multi-Config generator
• Clang 16+ or GCC 14+ or MSVC 17.4+

Test plan

• Verify header-based build still works
• Verify CMake configuration with modules enabled
• Verify all header directories exist
• Full module build test (requires compatible compiler)

Related

• Closes [MODULE] Create C++20 module files for kcenon.messaging #204
• Part of C++20 Module Migration Epic ([EPIC] C++20 Module Migration - Cross-System Preparation common_system#256)
• Depends on completed modules:
  • [MODULE] Create C++20 module files for kcenon.common common_system#269 (Tier 0) ✅
  • [MODULE] Create C++20 module files for kcenon.thread thread_system#371 (Tier 1) ✅
  • [MODULE] Create C++20 module files for kcenon.container container_system#222 (Tier 1) ✅
  • [MODULE] Create C++20 module files for kcenon.logger logger_system#275 (Tier 2) ✅
  • [MODULE] Create C++20 module files for kcenon.database database_system#314 (Tier 3) ✅
  • [MODULE] Create C++20 module files for kcenon.network network_system#395 (Tier 4) ✅