m13-domain-error

name	m13-domain-error
description	Mastering C++ Domain Errors: Exception Hierarchies, System Errors, and Expected.

C++ Domain Errors

Core Question

Who catches this?

• Exception: Inherit std::runtime_error.
• System Error: std::error_code (OS codes).

Thinking Prompt

1. Is it a Domain Event?

   • InsufficientFunds is an exception type.

2. Does it have context?

   • "File not found" needs "Which file?".
   • struct FileError : std::runtime_error { std::filesystem::path p; ... }

Quick Reference

Pattern	Use Case
std::runtime_error	Base for most failures.
std::logic_error	Bug (violation of precondition).
std::expected	Visible failure path.