I am reading through PHP Objects, Patterns and Practice 4th Ed and on  page 41, Constant Properties chapter says:Constant properties can contain only primitive values. You cannot assign an object to a constant.But objects are also primitive values according to the official documentation, as shown here: http://php.net/manual/en/language.types.intro.phpIs this an error in the book? It wouldn't be the only oneShould one try to report it? The book is quite old and I could not find an obvious place to report errorsHope this question is appropriate for [programmers.se] 
PHP primitive types: are objects primitive types?
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