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

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include <functional>
  11 #include <string>
  12
  13 template <class _Tp>
  14 struct is_transparent
  15 {
  16 private:
  17     struct __two {char __lx; char __lxx;};
  18     template <class _Up> static __two __test(...);
  19     template <class _Up> static char __test(typename _Up::is_transparent* = 0);
  20 public:
  21     static const bool value = sizeof(__test<_Tp>(0)) == 1;
  22 };
  23
  24
  25 int main () {
  26 #if _LIBCPP_STD_VER > 11
  27
  28     static_assert ( !is_transparent<std::less<int>>::value, "" );
  29     static_assert ( !is_transparent<std::less<std::string>>::value, "" );
  30     static_assert (  is_transparent<std::less<void>>::value, "" );
  31     static_assert (  is_transparent<std::less<>>::value, "" );
  32
  33     static_assert ( !is_transparent<std::less_equal<int>>::value, "" );
  34     static_assert ( !is_transparent<std::less_equal<std::string>>::value, "" );
  35     static_assert (  is_transparent<std::less_equal<void>>::value, "" );
  36     static_assert (  is_transparent<std::less_equal<>>::value, "" );
  37
  38     static_assert ( !is_transparent<std::equal_to<int>>::value, "" );
  39     static_assert ( !is_transparent<std::equal_to<std::string>>::value, "" );
  40     static_assert (  is_transparent<std::equal_to<void>>::value, "" );
  41     static_assert (  is_transparent<std::equal_to<>>::value, "" );
  42
  43     static_assert ( !is_transparent<std::not_equal_to<int>>::value, "" );
  44     static_assert ( !is_transparent<std::not_equal_to<std::string>>::value, "" );
  45     static_assert (  is_transparent<std::not_equal_to<void>>::value, "" );
  46     static_assert (  is_transparent<std::not_equal_to<>>::value, "" );
  47
  48     static_assert ( !is_transparent<std::greater<int>>::value, "" );
  49     static_assert ( !is_transparent<std::greater<std::string>>::value, "" );
  50     static_assert (  is_transparent<std::greater<void>>::value, "" );
  51     static_assert (  is_transparent<std::greater<>>::value, "" );
  52
  53     static_assert ( !is_transparent<std::greater_equal<int>>::value, "" );
  54     static_assert ( !is_transparent<std::greater_equal<std::string>>::value, "" );
  55     static_assert (  is_transparent<std::greater_equal<void>>::value, "" );
  56     static_assert (  is_transparent<std::greater_equal<>>::value, "" );
  57
  58 #endif
  59
  60     return 0;
  61     }