PHP_Compat, signature changes

Hello devs, There are a number of functions for which the function signature has changed. For example, microtime now has an added boolean, mkdir has a recursive switch, etc. I can replicate these changes, but people running version 4.3.11 and wanting the 5.0.3 function signature won't be able to load the function. There's a couple of options I'm considering... a) Functions with changed signatures live in a class. PHP_Compat_Component::microtime(...); b) Functions have php_compat affixed to them. php_compat_microtime(); c) Functions have another appropriate abbreviation, eg. phpc_microtime(); d) Functions have an underscore, or something affixed, _microtime(); If you have any suggestions, please let me know. Kind regards, Aidan