iphone: Unknown attribute 'objc

lundi 29 juin 2015

I'm trying to typedef a struct and box it into a dictionary value. I tried this code from the clang website, but no dice:

typedef struct __attribute__((objc_boxable)) _SizeA {
    CGFloat height;
    CGFloat width;
} SizeA;

The typedef is warned `Unknown attribute 'objc_boxable' ignored.

Xcode 6.3 with iOS SDK 8.3 targeting 8.0. Is there a trick here I'm missing?

iphone