李二狗 — @Meniny
Table of Content
The value of function OBJC_EXPORT void objc_setAssociatedObject(id object, const void *key, id value, objc_AssociationPolicy policy) must be an Objective-C object. We need to wrap the struct in an Objective-C class.
StructType s = ...;
NSValue* value = [NSValue valueWithBytes:&s objCType:@encode(StructType)];
objc_setAssociatedObject(obj, SPECIAL_KEY, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
// ...
NSValue* value = objc_getAssociatedObject(obj, SPECIAL_KEY);
StructType s;
[value getValue:&s];
