[libcxx] Remove redundant specializations in type_traits.

[MaskRay]

Ping :)

[ldionne]

include/type_traits

595

It is not impossible that this was a compile-time optimization for the (probably very common) case where there's only 2 arguments. I'd like to have Marshall's input on that, since he seems to have written that code. Otherwise, LGTM. Ping @mclow.lists

[ldionne]

LGTM, but you'll need to rebase this

[MaskRay]

Thanks for review! However, I am abandoning this change because rL364160 deleted these traits.

include/type_traits

 struct __lazy_and_impl;
 
 template <class ..._Preds>
 struct __lazy_and_impl<false, _Preds...> : false_type {};
 
 template <>
 struct __lazy_and_impl<true> : true_type {};
 
-template <class _Pred>
-struct __lazy_and_impl<true, _Pred> : integral_constant<bool, _Pred::type::value> {};
-
 template <class _Hp, class ..._Tp>
 struct __lazy_and_impl<true, _Hp, _Tp...> : __lazy_and_impl<_Hp::type::value, _Tp...> {};
 
 template <class _P1, class ..._Pr>
 struct __lazy_and : __lazy_and_impl<_P1::type::value, _Pr...> {};
 
 // __lazy_or
 

 struct __lazy_not : integral_constant<bool, !_Pred::type::value> {};
 
 // __and_
 template<class...> struct __and_;
 template<> struct __and_<> : true_type {};
 
 template<class _B0> struct __and_<_B0> : _B0 {};
 
-template<class _B0, class _B1>
-struct __and_<_B0, _B1> : conditional<_B0::value, _B1, _B0>::type {};
-
-template<class _B0, class _B1, class _B2, class... _Bn>
-struct __and_<_B0, _B1, _B2, _Bn...> 
-        : conditional<_B0::value, __and_<_B1, _B2, _Bn...>, _B0>::type {};
+template<class _B0, class _B1, class... _Bn>
+struct __and_<_B0, _B1, _Bn...>
+        : conditional<_B0::value, __and_<_B1, _Bn...>, _B0>::type {};
 
 // __or_
 template<class...> struct __or_;
 template<> struct __or_<> : false_type {};
 
 template<class _B0> struct __or_<_B0> : _B0 {};
 
-template<class _B0, class _B1>
-struct __or_<_B0, _B1> : conditional<_B0::value, _B0, _B1>::type {};
-
-template<class _B0, class _B1, class _B2, class... _Bn>
-struct __or_<_B0, _B1, _B2, _Bn...> 
-        : conditional<_B0::value, _B0, __or_<_B1, _B2, _Bn...> >::type {};
+template<class _B0, class _B1, class... _Bn>
+struct __or_<_B0, _B1, _Bn...>
+        : conditional<_B0::value, _B0, __or_<_B1, _Bn...> >::type {};
 
 // __not_
 template<class _Tp> 
 struct __not_ : conditional<_Tp::value, false_type, true_type>::type {};
 
 #endif // !defined(_LIBCPP_CXX03_LANG)
 
 // is_const