Encode and Decode objects without making typos

stringify

Taken From: http://stablekernel.com/blog/speeding-up-nscoding-with-macros/

#define OBJC_STRINGIFY(x) @#x
#define encodeObject(x) [aCoder encodeObject:x forKey:OBJC_STRINGIFY(x)]
#define decodeObject(x) x = [aDecoder decodeObjectForKey:OBJC_STRINGIFY(x)]
#define encodeFloat(x) [aCoder encodeFloat:x forKey:OBJC_STRINGIFY(x)]
#define decodeFloat(x) x = [aDecoder decodeFloatForKey:OBJC_STRINGIFY(x)]

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super init];
    if(self) {
        decodeObject(_obj);
        decodeFloat(someFloat);
    }
    return self;
}
- (void)encodeWithCoder:(NSCoder *)aCoder
{
    encodeObject(_obj);
    encodeFloat(someFloat);
}