ceph/src/boost/libs/type_traits/test/detected_test.cpp

   1 /*
   2 Copyright 2017 Glen Joseph Fernandes
   3 <glenjofe -at- gmail.com>
   4
   5 Distributed under the Boost Software License,
   6 Version 1.0. (See accompanying file LICENSE_1_0.txt
   7 or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 */
   9 #include <boost/config.hpp>
  10 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
  11     !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
  12 #ifdef TEST_STD
  13 #include <type_traits>
  14 #else
  15 #include <boost/type_traits/detected.hpp>
  16 #endif
  17 #include "check_integral_constant.hpp"
  18 #include "check_type.hpp"
  19
  20 #define CHECK_FALSE(e) BOOST_CHECK_INTEGRAL_CONSTANT(e, false)
  21 #define CHECK_TRUE(e) BOOST_CHECK_INTEGRAL_CONSTANT(e, true)
  22
  23 template<class T>
  24 using type_t = typename T::type;
  25
  26 struct has_type {
  27     using type = char;
  28 };
  29
  30 struct no_type { };
  31
  32 TT_TEST_BEGIN(detected)
  33
  34 BOOST_CHECK_TYPE3(::tt::detected_t<type_t, int>, boost::nonesuch);
  35 BOOST_CHECK_TYPE3(::tt::detected_t<type_t, has_type>, char);
  36 BOOST_CHECK_TYPE3(::tt::detected_t<type_t, no_type>, boost::nonesuch);
  37
  38 TT_TEST_END
  39 #else
  40 int main()
  41 {
  42     return 0;
  43 }
  44 #endif