Stream stream = Stream.of(1, 2, 3); //Will compile fine
IntStream intStream = IntStream.of(4, 5, 6); //Will compile fine

Stream s = IntStream.of(4, 5, 6); //Does not compile
Stream s = IntStream.of(4, 5, 6).mapToObj(e -> e); //mapToObj method is needed
IntStream is = Stream.of(4, 5, 6).mapToInt(e -> e); //mapToInt method is needed