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What is the availability of NSNotFound?

This in-Xcode documentation for NSNotFound is quite confusing:

It says "Available in iOS 2.0 through 8.4" and "Availability: iOS 8.1 to 8.0". So... Is it available before 8.0? Or in 9.0+? Also, what's going on here, if it is?

Solution

  • Insert availabilityOfNSNotFound == NSNotFound joke here.

    At some point when Apple was pushing mandatory 64-bit device support (iOS 8.4 SDK?), the declaration of NSNotFound was changed from:

    enum {NSNotFound = NSIntegerMax};

    to

    static const NSInteger NSNotFound = NSIntegerMax;

    You can verify this in <Foundation/NSObjCRuntime.h>.

    The documentation was never changed, so the availability of the enum NSNotFound is no longer in the SDK. But as of iOS 9 and above, the static const NSInteger NSNotFound is available.

    Although I cannot answer the true availability of NSNotFound since I don't work for Apple (as a developer I think it's safe to use in all iOS versions since 2.0, or else a lot of Foundation classes would break since they can return NSNotFound), you can check to see if the memory location for NSNotFound is NULL:

    #pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wtautological-compare"
BOOL found = (&NSNotFound != NULL);
#pragma clang diagnostic pop
if (found) {
    NSLog(@"meh");
}