http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46778
Summary: More SFINAE issues?
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: [email protected]
ReportedBy: [email protected]
I'm working on updating std::is_constructible and I see behavior I don't
understand for the current implementation. Shouldn't the below just compile???
(a more refined version of the code using std::declval<_Args1>(), etc, as in
<type_traits> doesn't change anything)
template<typename _Tp, typename... _Args>
class is_constructible_mini
{
typedef char __one;
typedef struct { char __arr[2]; } __two;
template<typename _Tp1, typename... _Args1>
static decltype(_Tp1(_Args1()...), __one())
__test(int);
template<typename, typename...>
static __two __test(...);
public:
static const bool value = sizeof(__test<_Tp, _Args...>(0)) == 1;
};
int t1[is_constructible_mini<int&>::value ? -1 : 1];
int t2[is_constructible_mini<const int&>::value ? -1 : 1];
int t3[is_constructible_mini<int&, int, int>::value ? -1 : 1]; // Ok
int t4[is_constructible_mini<const int&, int, int>::value ? -1 : 1];
