the log domain, or NULL for the default "" application domain
the log levels to apply the log handler for. To handle fatal and recursive messages as well, combine the log levels with the G_LOG_FLAG_FATAL and G_LOG_FLAG_RECURSION bit flags.
the log handler function
data passed to the log handler
destroy notify for user_data, or NULL
the id of the new handler
2.46
Like g_log_set_handler(), but takes a destroy notify for the user_data.
This has no effect if structured logging is enabled; see [Using Structured Logging][using-structured-logging].