added asio

include/asio/detail/future.hpp

@@ -0,0 +1,32 @@
+//
+// detail/future.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_FUTURE_HPP
+#define ASIO_DETAIL_FUTURE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <future>
+
+// Even though the future header is available, libstdc++ may not implement the
+// std::future class itself. However, we need to have already included the
+// future header to reliably test for _GLIBCXX_HAS_GTHREADS.
+#if defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+# if defined(_GLIBCXX_HAS_GTHREADS)
+#  define ASIO_HAS_STD_FUTURE_CLASS 1
+# endif // defined(_GLIBCXX_HAS_GTHREADS)
+#else // defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+# define ASIO_HAS_STD_FUTURE_CLASS 1
+#endif // defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+
+#endif // ASIO_DETAIL_FUTURE_HPP