ceph/src/boost/libs/callable_traits/example/return_type.cpp

   1 /*!<-
   2 Copyright (c) 2016 Barrett Adair
   3
   4 Distributed under the Boost Software License, Version 1.0.
   5 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   6 ->*/
   7
   8 #include <boost/callable_traits/detail/config.hpp>
   9 #ifdef BOOST_CLBL_TRTS_DISABLE_ABOMINABLE_FUNCTIONS
  10 int main(){ return 0; }
  11 #else
  12
  13 //[ return_type
  14 #include <type_traits>
  15 #include <boost/callable_traits.hpp>
  16
  17 namespace ct = boost::callable_traits;
  18
  19 using expect = int;
  20
  21 struct foo;
  22
  23 template<typename T>
  24 void test() {
  25     using result = ct::return_type_t<T>;
  26     static_assert(std::is_same<expect, result>{}, "");
  27 }
  28
  29 int main() {
  30
  31     test<int()>();
  32     test<int(*)()>();
  33     test<int(&)()>();
  34     test<int() const>();
  35     test<int(foo::*)() const>();
  36
  37     auto x = []() -> int { return 0; };
  38
  39     test<decltype(x)>();
  40 }
  41 //]
  42 #endif //#ifdef BOOST_CLBL_TRTS_DISABLE_ABOMINABLE_FUNCTIONS