What does ((void (*)())buf)(); mean?

Question

I am solving a binary exploitation challenge on picoCTF and came across this piece of code:

((void (*)())buf)();

where buf is a character array.

I solved the challenge but can't seem to understand what exactly it's doing. I looked at this thread but I couldn't make it out.

What does ((void (*)())buf)(); mean?

Answer 1

void (*)() is a type, the type being "pointer to function that takes indeterminate arguments and returns no value".

(void (*)()) is a type-cast to the above type.

(void (*)())buf casts buf to the above type.

((void (*)())buf)() calls the function (passing no arguments).

In short: It tells the compiler to treat buf as a pointer to a function, and to call that function.