-sizeWithFont functions differently on the device

Question

Thus, I seem to encounter some weird behavior when using NSString -sizeWithFontmethod call families depending on whether I call it on the iPhone Simulator or the actual device.

Simple enough, when the receiver of the method call -sizeWithFont:constrainedToSize:lineBreakMode: nil, the resultant CGSize, passed back to the simulator, is equal {0, 0}. However, on the device, the return result is the same value CGSizethat I specify in the method call as a parameter constrainedToSize:. See the following log statements:

Simulator:

someString: (null)
someStringSize: {0, 0}

Device:

someString: (null)
someStringSize: {185, 3.40282e+38}

The behavior on the Simulator is what I would expect. It's not that this question is hard to get around, but 1) I'm a bit confused, why does this family of functions behave differently on the Simulator and the actual device, and 2) why does calling the method in the receiver nilreturn a specific, deterministic result?

Thanks for any pointers or insights that you guys can provide!

EDIT . I believe that I should mention that I am building against the 3.1 SDK.

Answer 1

Apple's documentation on Sending Messages in nil explains this:

, nil, :

• , , nil, 0 (nil)...
• , sizeof (void *), float, double, long double long long, , nil, 0.
• , Mac OS X ABI Function Call Guide, , to nil 0.0 . .
• , , , nil, undefined.

iPhone ( iPhone SDK), : (, CGSize), . , CPU, . ARM iPhone, , iPhone sizeWithFont: , i386. , undefined iPhone.