Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.std.c++ > #568

Re: Private access in partial specialization definitions

Show all headers | View raw

Am 14.12.2012 18:20, schrieb maowfijwef@amfoijefa.ca:
> GCC's behavior differs from Clang and Visual C++ in the following examples:
>
> #include<type_traits>
>
> template<typename T, typename Enabler = void>
> struct test1 : std::false_type {};
>
> template<typename T>
> struct test1<T, typename T::typedef_test>  : std::true_type {};
>
> template<typename T, typename Enabler = void>
> struct test2 : std::false_type {};
>
> template<typename T>
> struct test2<T,
>       typename std::enable_if<
>           T::enum_test,
>           void
>       >::type>  : std::true_type {};
>
> struct object
> {
>       template<typename T, typename Enabler>
>       friend struct test1;
>
>       template<typename T, typename Enabler>
>       friend struct test2;
>
>       private:
>           enum { enum_test = true };
>           typedef void typedef_test;
> };
>
> // test1
> static_assert(test1<object>::value, "failed");
>
> // test2
> static_assert(test2<object>::value, "failed");
>
> Results (compiler, test1, test2):
> g++ (4.7.2), pass, fail
> g++ (4.8.0), fail, fail
> clang++ (3.3), pass, pass
> Visual C++ 2012, pass, pass
>
> Which is correct?  I'd appreciate direction to the relevant sections of
> the standard if at all possible.

With the resolution of the issue

http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#580

the code should be well-formed. It looks to me as if gcc hasn't yet
applied the resolution. I suggest to open a compiler bug for this.

HTH & Greetings from Bremen,

Daniel Krügler




-- 
[ comp.std.c++ is moderated.  To submit articles, try posting with your ]
[ newsreader.  If that fails, use mailto:std-cpp-submit@vandevoorde.com ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.comeaucomputing.com/csc/faq.html                      ]

Back to comp.std.c++ | Previous | Next — Previous in thread | Find similar

Thread

Private access in partial specialization definitions maowfijwef@amfoijefa.ca - 2012-12-14 09:20 -0800
  Re: Private access in partial specialization definitions Daniel Krügler <daniel.kruegler@googlemail.com> - 2012-12-15 10:53 -0800

csiph-web