Question

Here is a part of Apple code.

I don’t understand the first line. Why is there a “void” with a return ?

// forward declaration of our utility functions
static NSUInteger _ImageCount(void);

static NSUInteger _ImageCount(void)
{
    static NSUInteger count = 0;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        count = [_ImageData() count];
    });
return count;
}

Answer 1

foo(void) means that the function does not expect any parameter. But it does return and NSUInteger.

static NSUInteger _ImageCount(void)
^      ^          ^           ^
|      |          |           parameter list
|      |          function name
|      return type
visibility (may be referenced only from this module)