Summary

Remove or consolidate core/deprecation.h in container_system to simplify the codebase for C++20 module migration, following Kent Beck's "Fewest Elements" principle.

Parent Epic

Part of kcenon/common_system#256 (C++20 Module Migration - Cross-System Preparation)

Current State

File Location

include/container/core/deprecation.h

Problem Analysis

C++20 Module Impact

Deprecation headers add complexity to module boundaries:

export module kcenon.container;
// deprecation.h should not be part of public module interface

Proposed Solution

Option 1: Remove file entirely

• Replace custom deprecation macros with [[deprecated("message")]]
• C++14+ standard attribute is sufficient

Option 2: Move to internal namespace

• If custom deprecation tracking is needed
• Move to detail:: or internal:: namespace

Tasks

• Audit deprecation.h contents and usage
• Identify all uses of custom deprecation macros
• Replace with standard [[deprecated]] attribute
• Remove deprecation.h if no longer needed
• Update documentation

Acceptance Criteria

• No custom deprecation mechanisms where standard suffices
• Clean module boundary for C++20 migration
• All tests pass
• No breaking changes to public API

Related

• C++20 Module Migration Epic ([EPIC] C++20 Module Migration - Cross-System Preparation common_system#256)
• Kent Beck "Fewest Elements" principle