ceph/src/boost/libs/callable_traits/test/class_of_constraints.cpp

   1
   2 /*
   3 Copyright Barrett Adair 2016-2017
   4
   5 Distributed under the Boost Software License, Version 1.0.
   6 (See accompanying file LICENSE.md or copy at http ://boost.org/LICENSE_1_0.txt)
   7
   8 */
   9
  10 #include <boost/callable_traits/class_of.hpp>
  11 #include "test.hpp"
  12
  13 struct foo;
  14
  15 template<typename T>
  16 struct is_substitution_failure_class_of {
  17
  18     template<typename>
  19     static auto test(...) -> std::true_type;
  20
  21     template<typename A,
  22         typename std::remove_reference<
  23             TRAIT(class_of, A)>::type* = nullptr>
  24     static auto test(int) -> std::false_type;
  25
  26     static constexpr bool value = decltype(test<T>(0))::value;
  27 };
  28
  29 int main() {
  30
  31     auto lambda = [](){};
  32
  33     CT_ASSERT(is_substitution_failure_class_of<decltype(lambda)>::value);
  34     CT_ASSERT(is_substitution_failure_class_of<decltype(lambda)&>::value);
  35     CT_ASSERT(is_substitution_failure_class_of<void>::value);
  36     CT_ASSERT(is_substitution_failure_class_of<void*>::value);
  37     CT_ASSERT(is_substitution_failure_class_of<int>::value);
  38     CT_ASSERT(is_substitution_failure_class_of<int &>::value);
  39     CT_ASSERT(is_substitution_failure_class_of<int()>::value);
  40     CT_ASSERT(is_substitution_failure_class_of<int(*)()>::value);
  41     CT_ASSERT(is_substitution_failure_class_of<int(**)()>::value);
  42     CT_ASSERT(is_substitution_failure_class_of<int(&)()>::value);
  43     CT_ASSERT(is_substitution_failure_class_of<int (foo::** const)()>::value);
  44 }
  45