Summary

• Add C++20 module files for container_system as part of the Tier 1 core libraries
• Create src/modules/container.cppm with complete module interface
• Update CMakeLists.txt with CONTAINER_BUILD_MODULES option for module build

Changes

Module Structure

• Primary module: kcenon.container
• Dependencies: kcenon.common (Tier 0)
• File: src/modules/container.cppm

Exported Types

• value_types enumeration
• value_variant (SOO storage type)
• optimized_value structure
• pool_stats structure
• value_container class with full API
• variant_helpers namespace (JSON/XML encoding utilities)

CMake Configuration

• New option: CONTAINER_BUILD_MODULES (default: OFF)
• Requires CMake 3.28+ for module scanning
• Requires Ninja or Visual Studio 2022 17.4+ generator
• Creates container_system_modules target with kcenon::container_modules alias

Requirements

• CMake 3.28 or later
• Ninja generator (or VS 2022 17.4+)
• Clang 16+, GCC 14+, or MSVC 2022 17.4+
• kcenon.common module (from common_system)

Test Plan

• Header-based build continues to work
• All 85 existing tests pass
• CMake configuration succeeds with CONTAINER_BUILD_MODULES=OFF
• CMake configuration succeeds with CONTAINER_BUILD_MODULES=ON (with appropriate generator)
• Module-based build compiles (requires Ninja + common_system modules)

Related Issues

• Closes [MODULE] Create C++20 module files for kcenon.container #222
• Part of [EPIC] C++20 Module Migration - Cross-System Preparation common_system#256 (C++20 Module Migration - Cross-System Preparation)
• Prerequisites completed:
  • [REFACTOR] Remove deprecation.h - C++20 Module preparation #221 (Remove deprecation.h) - COMPLETED
  • [MODULE] Create C++20 module files for kcenon.common common_system#269 (common_system module) - COMPLETED