Re: [Boost-users] Using SFINAE to detect presence of member function - Unreliable

Subject: Re: [Boost-users] Using SFINAE to detect presence of member function - Unreliable
From: Roman Perepelitsa (roman.perepelitsa_at_[hidden])
Date: 2009-02-03 05:02:49

2009/2/2 Naik, Roshan <roshan.naik_at_[hidden]>

>  Seems like the following specialization of impl<> works:
>
>
>
>
>
>    template <typename r>
>
>    struct impl<true, r(void)>
>
>    {
>
>      static const bool value =
>
>        sizeof(
>
>             return_value_check<type, r>::deduce( (
>
>              (((derived_type*)0)->operator()(),
> details::void_exp_result<type>())
>
>                          ) )
>
>             ) == sizeof(yes);
>
>
>
>    };
>

I don't think it does. Try this test:

struct foo {
   void operator()() const {}
};

int main() {
  is_call_possible<foo, void()>::value;
}

Roman Perepelitsa.