Oh, that clears everything, please ignore my previous post. Still,
don't you think this is a bit misleading? IMHO, new object should
always have the unique id(or hash in terms of spl)...
I don't like it either;) But it does exactly what Stanislav Malyshev described: it hashes the "tuple of C pointer". Misleading in this case is that this is only unique as long as the compared objects exist at the same time...then they can't inhabit the same memory-space. But because php clears and reuses memory as soon as no pointers to the object exist (reference counting). In this case php uses the exact same "tuple of C pointer" for the next object as the for the previous one. At least...that's my interpretation of this behaviour;)