LazyGetterMacro.h

/**
 * Lazily initializes an object.  Mainly used for reducing boilerplate code.
 */
#define DEFINE_LAZY_GETTER(type, name, initialValueBlock) \
    - (type)name { \
        if (! _ ## name) { \
            _ ## name = initialValueBlock(); \
        } \
        return _ ## name; \
    }

LazyGetterMacro.m

// example usage
DEFINE_LAZY_GETTER( Person *, homeOwner, ^{
    return [Person new];
});