Private access in partial specialization definitions

[maowf...@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.


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[Daniel Krügler]

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 Kr�gler