Is void** an acceptable type in ANSI-C?

Question

I have seen a function whose prototype is:

int myfunc(void** ppt)

This function is called in a C file as a = myfunc(mystruct **var1);<

Answer 1

void** is valid but, based on your error message, you probably have to explicitly cast the argument as follows:

mystruct **var1;
x = myfunc ((void**) var1);

That's because the myfunc function is expecting the void** type. While void* can be implicitly cast to any other pointer, that is not so for the double pointer - you need to explicitly cast it.