search for: __is_assignable_test

...at circumstances the library can use constructs which could depend on the completeness of user-provided types) but I suspect it is not, and even if it were, we'd want to allow this as a QoI issue. Here's a fix (first change: avoid overloaded 'operator,', second change: avoid ADL for __is_assignable_test): --- type_traits (revision 164877) +++ type_traits (working copy) @@ -1187,10 +1187,15 @@ #endif // _LIBCPP_HAS_NO_VARIADICS +template <class _Fst, class _Snd> +struct __select_2nd { + typedef _Snd type; +}; + // is_assignable template <class _Tp, class _Arg> -decltype((_VSTD...

...at circumstances the library can use constructs which could depend on the completeness of user-provided types) but I suspect it is not, and even if it were, we'd want to allow this as a QoI issue. Here's a fix (first change: avoid overloaded 'operator,', second change: avoid ADL for __is_assignable_test): > > > --- type_traits (revision 164877) > +++ type_traits (working copy) > @@ -1187,10 +1187,15 @@ > > #endif // _LIBCPP_HAS_NO_VARIADICS > > +template <class _Fst, class _Snd> > +struct __select_2nd { > + typedef _Snd type; > +}; > + > //...

On Sep 28, 2012, at 5:54 PM, Richard Smith <richard at metafoo.co.uk> wrote: > Reduced testcase: > > template<typename T> struct A { typedef decltype(T() + 0) type; }; > template<typename T> struct B { > struct C { typedef typename A<C*>::type type; }; > typedef typename A<C*>::type type; > }; > B<int> b; > > ... produces ...

...type((_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>(), true_type())) > > ^ > > /usr/bin/../lib/c++/v1/type_traits:1186:1: note: while substituting > > deduced template arguments into function template > > '__is_assignable_test' [with _Tp = Templ8<int>::Member *&, _Arg = <no > > value>] > > __is_assignable_test(_Tp&&, _Arg&&); > > ^ > > /usr/bin/../lib/c++/v1/type_traits:1214:14: note: in instantiation of > > template class 'std::__1::__is_assignable_im...

...nt>::Member' requested here decltype((_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>(), true_type())) ^ /usr/bin/../lib/c++/v1/type_traits:1186:1: note: while substituting deduced template arguments into function template '__is_assignable_test' [with _Tp = Templ8<int>::Member *&, _Arg = <no value>] __is_assignable_test(_Tp&&, _Arg&&); ^ /usr/bin/../lib/c++/v1/type_traits:1214:14: note: in instantiation of template class 'std::__1::__is_assignable_imp<Templ8<int>::Member *&, Templ8<i...

...ested here > decltype((_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>(), true_type())) > ^ > /usr/bin/../lib/c++/v1/type_traits:1186:1: note: while substituting > deduced template arguments into function template > '__is_assignable_test' [with _Tp = Templ8<int>::Member *&, _Arg = <no > value>] > __is_assignable_test(_Tp&&, _Arg&&); > ^ > /usr/bin/../lib/c++/v1/type_traits:1214:14: note: in instantiation of > template class 'std::__1::__is_assignable_imp<Templ8<int>::M...

...lval<_Tp>() = _VSTD::declval<_Arg>(), true_type())) >> > ^ >> > /usr/bin/../lib/c++/v1/type_traits:1186:1: note: while substituting >> > deduced template arguments into function template >> > '__is_assignable_test' [with _Tp = Templ8<int>::Member *&, _Arg = <no >> > value>] >> > __is_assignable_test(_Tp&&, _Arg&&); >> > ^ >> > /usr/bin/../lib/c++/v1/type_traits:1214:14: note: in instantiation of >> > template class 'std::__1...

...::declval<_Arg>(), > true_type())) > >> > ^ > >> > /usr/bin/../lib/c++/v1/type_traits:1186:1: note: while substituting > >> > deduced template arguments into function template > >> > '__is_assignable_test' [with _Tp = Templ8<int>::Member *&, _Arg = <no > >> > value>] > >> > __is_assignable_test(_Tp&&, _Arg&&); > >> > ^ > >> > /usr/bin/../lib/c++/v1/type_traits:1214:14: note: in instantiation of > >> > tem...