ceph/src/boost/libs/hana/test/detail/decay.cpp

   1 // Copyright Louis Dionne 2013-2017
   2 // Distributed under the Boost Software License, Version 1.0.
   3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   4
   5 #include <boost/hana/detail/decay.hpp>
   6
   7 #include <type_traits>
   8 namespace hana = boost::hana;
   9
  10
  11 template <typename T, typename Decayed>
  12 void check() {
  13     static_assert(std::is_same<
  14         typename hana::detail::decay<T>::type,
  15         Decayed
  16     >::value, "");
  17 }
  18
  19 int main() {
  20     // void is untouched
  21     check<void, void>();
  22
  23     // normal types lose cv-qualifiers
  24     check<int, int>();
  25     check<int const, int>();
  26     check<int const volatile, int>();
  27
  28     // [cv-qualified] references are stripped
  29     check<int&, int>();
  30     check<int const&, int>();
  31     check<int&&, int>();
  32     check<int const&&, int>();
  33
  34     // pointers are untouched
  35     check<int*, int*>();
  36     check<int const*, int const*>();
  37     check<int volatile*, int volatile*>();
  38     check<int const volatile*, int const volatile*>();
  39
  40     // arrays decay to pointers
  41     check<int[], int*>();
  42     check<int[10], int*>();
  43     check<int const[10], int const*>();
  44     check<int volatile[10], int volatile*>();
  45     check<int const volatile[10], int const volatile*>();
  46
  47     // functions decay to function pointers
  48     check<void(), void(*)()>();
  49     check<void(...), void (*)(...)>();
  50     check<void(int), void(*)(int)>();
  51     check<void(int, ...), void(*)(int, ...)>();
  52     check<void(int, float), void(*)(int, float)>();
  53     check<void(int, float, ...), void(*)(int, float, ...)>();
  54 }