Validate complex types

Hello I'm wondering if there is a recommended way to validate a multi-type parameter in an internal function. If a parameter is expected to be "long or string" or to be "integer or null", a simple call to zend_parse_parameters() won't validate it. I read some extensions' code, and it seems that the preferred method is to call zend_parse_parameters(_ex) several times until one validation succeeds or all fail. I really don't like this solution. Maybe the performance penalty of parsing twice the arguments is negligible, but I don't even like the idea of this code. Isn't there a better solution? Or did I miss a good reason for this? I wanted to use zend_parse_arg() to validate a single parameter if the first call to zend_parse_parameters_ex() wasn't successful. But this function is never used outside of "Zend/zend_API.c". Is it meant for public use? Are there any drawbacks in calling it? Regards -- François Gannaz