First half of support for N3657; heterogenous lookups for set/multiset git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188241 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__functional_base b/include/__functional_base index 8ecc35b..72da759 100644 --- a/include/__functional_base +++ b/include/__functional_base
@@ -68,6 +68,7 @@ template <class _T1, class _T2> _LIBCPP_INLINE_VISIBILITY auto operator()(_T1&& __t, _T2&& __u) const { return _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u); } + typedef void is_transparent; }; #endif @@ -501,6 +502,20 @@ #endif // _LIBCPP_HAS_NO_VARIADICS +#if _LIBCPP_STD_VER > 11 +template <class _Tp1, class _Tp2 = void> +struct __is_transparent +{ +private: + struct __two {char __lx; char __lxx;}; + template <class _Up> static __two __test(...); + template <class _Up> static char __test(typename _Up::is_transparent* = 0); +public: + static const bool value = sizeof(__test<_Tp1>(0)) == 1; +}; +#endif + + _LIBCPP_END_NAMESPACE_STD #endif // _LIBCPP_FUNCTIONAL_BASE 