[saagarjha]

objc_msgSend accepts a variable number of arguments, and it needs to forward those to the method implementation. This is not possible to do in pure C.

[colejohnson66]

What about just forwarding the var_args variable?

[saagarjha]

You'd have to pass around a va_list everywhere and parse it at the call site. This adds overhead that you probably don't want to deal with, especially since objc_msgSend is probably the hottest code path in any Objective-C program.