NS_VALID_UNTIL_END_OF_SCOPE
Marks local variables of type id or pointer-to-ObjC-object-type so that values stored into those local variable are not aggressively released by the compiler during optimization. Instead, the values are held until either the variable is assigned to again, or the end of the scope of the local variable (such as in a compound statement or a method definition).
Declaration
#define NS_VALID_UNTIL_END_OF_SCOPE