What does Class::* do?

Asked Jun 08 '16 at 15:30

Active Jun 08 '16 at 15:30

Viewed 121 times

I've seen some examples for implementing is_class recently, and I'm wondering what the following syntax does:

Classname::*

For example:

template<typename T>
class is_class {
    typedef char yes[1];
    typedef char no [2];
    template<typename C> static yes& test(int C::*); // selected if C is a class type
    template<typename C> static no&  test(...);      // selected otherwise
  public:
    static bool const value = sizeof(test<T>(0)) == sizeof(yes);
}

What does the syntax C::* denote in this case? Does it just require C to have any members / be a namespace? I was unable to find any information about this.

asked Jun 08 '16 at 15:30

tobspr

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It is the syntax for a [pointer to a data member](http://en.cppreference.com/w/cpp/language/pointer) – Cory Kramer Jun 08 '16 at 15:34
@CoryKramer Thanks. I wasn't 100% sure if I should use it or not. – NathanOliver Jun 08 '16 at 15:36
What does it mean without a member name though? – tobspr Jun 08 '16 at 15:38
2

@tobspr The same thing. It is a function declaration parameter so it does not have to have a name. – NathanOliver Jun 08 '16 at 15:40

What does Class::* do?

0 Answers0