1 Nullable!int empty; 2 Nullable!int a = 42; 3 Nullable!int b = 42; 4 Nullable!int c = 27; 5 6 assert(empty == empty); 7 assert(empty == Nullable!int.init); 8 assert(empty != a); 9 assert(empty != b); 10 assert(empty != c); 11 12 assert(a == b); 13 assert(a != c); 14 15 assert(empty != 42); 16 assert(a == 42); 17 assert(c != 42);
If they are both null, then they are equal. If one is null and the other is not, then they are not equal. If they are both non-null, then they are equal if their values are equal.