ceph/src/spawn/include/spawn/detail/is_stack_allocator.hpp

   1 //
   2 // detail/is_stack_allocator.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2019 Casey Bodley (cbodley at redhat dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #pragma once
  12
  13 #include <type_traits>
  14
  15 #include <boost/type_traits/make_void.hpp>
  16
  17 namespace spawn::detail {
  18
  19 template <typename T, typename = void>
  20 struct is_stack_allocator : std::false_type {};
  21
  22 template <typename T>
  23 struct is_stack_allocator<T, boost::void_t<decltype(
  24     // boost::context::stack_context c = salloc.allocate();
  25     std::declval<boost::context::stack_context>() = std::declval<T&>().allocate(),
  26     // salloc.deallocate(c);
  27     std::declval<T&>().deallocate(std::declval<boost::context::stack_context&>())
  28     )>> : std::true_type {};
  29
  30 } // namespace spawn::detail