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
Return: the id of the new handler
2.46
Like g_log_sets_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].