src/third_party/libc++/trunk/test/utilities/function.objects/comparisons/transparent.pass.cpp

   1 #include <functional>
   2 #include <string>
   3
   4 template <class _Tp>
   5 struct is_transparent
   6 {
   7 private:
   8     struct __two {char __lx; char __lxx;};
   9     template <class _Up> static __two __test(...);
  10     template <class _Up> static char __test(typename _Up::is_transparent* = 0);
  11 public:
  12     static const bool value = sizeof(__test<_Tp>(0)) == 1;
  13 };
  14
  15
  16 int main () {
  17 #if _LIBCPP_STD_VER > 11
  18
  19     static_assert ( !is_transparent<std::less<int>>::value, "" );
  20     static_assert ( !is_transparent<std::less<std::string>>::value, "" );
  21     static_assert (  is_transparent<std::less<void>>::value, "" );
  22     static_assert (  is_transparent<std::less<>>::value, "" );
  23
  24     static_assert ( !is_transparent<std::less_equal<int>>::value, "" );
  25     static_assert ( !is_transparent<std::less_equal<std::string>>::value, "" );
  26     static_assert (  is_transparent<std::less_equal<void>>::value, "" );
  27     static_assert (  is_transparent<std::less_equal<>>::value, "" );
  28
  29     static_assert ( !is_transparent<std::equal_to<int>>::value, "" );
  30     static_assert ( !is_transparent<std::equal_to<std::string>>::value, "" );
  31     static_assert (  is_transparent<std::equal_to<void>>::value, "" );
  32     static_assert (  is_transparent<std::equal_to<>>::value, "" );
  33
  34     static_assert ( !is_transparent<std::not_equal_to<int>>::value, "" );
  35     static_assert ( !is_transparent<std::not_equal_to<std::string>>::value, "" );
  36     static_assert (  is_transparent<std::not_equal_to<void>>::value, "" );
  37     static_assert (  is_transparent<std::not_equal_to<>>::value, "" );
  38
  39     static_assert ( !is_transparent<std::greater<int>>::value, "" );
  40     static_assert ( !is_transparent<std::greater<std::string>>::value, "" );
  41     static_assert (  is_transparent<std::greater<void>>::value, "" );
  42     static_assert (  is_transparent<std::greater<>>::value, "" );
  43
  44     static_assert ( !is_transparent<std::greater_equal<int>>::value, "" );
  45     static_assert ( !is_transparent<std::greater_equal<std::string>>::value, "" );
  46     static_assert (  is_transparent<std::greater_equal<void>>::value, "" );
  47     static_assert (  is_transparent<std::greater_equal<>>::value, "" );
  48
  49 #endif
  50
  51     return 0;
  52     }