I would shy away from the word "intersection" (though it would calculate one), since we're explicitly not finding an intersection (in one dimension). What you are trying to calculate is the (component-wise) median of the rectangle edges.

I also wonder about declaring a ```CGRect``` and using ```NSMinX``` on it, though I know it works and it seems to be accepted practice in Rebel.

Something like the following makes a little more sense to me, given that:

```obj-c
#import <tgmath.h> // Generic math!

static CGFloat CGRectGetMedianX(CGRect r1, CGRect r2)
{
    CGFloat minX = fmax(NSMinX(r1), NSMinX(r2));
    CGFloat maxX = fmin(NSMaxX(r1), NSMaxX(r2));
    return (minX + maxX) / 2;
}
```