1 //
2 // is_read_buffered.hpp
3 // ~~~~~~~~~~~~~~~~~~~~
4 //
5 // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff 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 #ifndef BOOST_ASIO_IS_READ_BUFFERED_HPP
12 #define BOOST_ASIO_IS_READ_BUFFERED_HPP
13 
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
15 # pragma once
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17 
18 #include <boost/asio/detail/config.hpp>
19 #include <boost/asio/buffered_read_stream_fwd.hpp>
20 #include <boost/asio/buffered_stream_fwd.hpp>
21 
22 #include <boost/asio/detail/push_options.hpp>
23 
24 namespace boost {
25 namespace asio {
26 
27 namespace detail {
28 
29 template <typename Stream>
30 char is_read_buffered_helper(buffered_stream<Stream>* s);
31 
32 template <typename Stream>
33 char is_read_buffered_helper(buffered_read_stream<Stream>* s);
34 
35 struct is_read_buffered_big_type { char data[10]; };
36 is_read_buffered_big_type is_read_buffered_helper(...);
37 
38 } // namespace detail
39 
40 /// The is_read_buffered class is a traits class that may be used to determine
41 /// whether a stream type supports buffering of read data.
42 template <typename Stream>
43 class is_read_buffered
44 {
45 public:
46 #if defined(GENERATING_DOCUMENTATION)
47   /// The value member is true only if the Stream type supports buffering of
48   /// read data.
49   static const bool value;
50 #else
51   BOOST_ASIO_STATIC_CONSTANT(bool,
52       value = sizeof(detail::is_read_buffered_helper((Stream*)0)) == 1);
53 #endif
54 };
55 
56 } // namespace asio
57 } // namespace boost
58 
59 #include <boost/asio/detail/pop_options.hpp>
60 
61 #endif // BOOST_ASIO_IS_READ_BUFFERED_HPP
62