cbeam/error/system_error.hpp

throw cbeam::error::system_error("Custom error message");

Under the hood:

• On Windows platforms, this class uses GetLastError() to retrieve the last error code set by the Windows API, and std::system_category() to categorize the error as a system-specific error. This is suitable for errors that are specific to the Windows API and its various system calls.
• On Unix-based platforms (like Linux and macOS), the class uses errno for the error code, which is the standard way of reporting errors in POSIX-compliant systems. It utilizes std::generic_category() for the error category, reflecting the more generic nature of errno. This is appropriate since errno covers a wide range of error conditions that are not limited to specific system calls.

Rationale: The differentiation between std::system_category() on Windows and std::generic_category() on Unix-based systems allows for more accurate representation of errors in a platform-specific manner. std::system_category() is used on Windows to align with the Windows-specific error codes provided by GetLastError(), while std::generic_category() is used on Unix-based systems for its broader applicability across various types of errors indicated by errno.