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							- //
 - // completion_condition.hpp
 - // ~~~~~~~~~~~~~~~~~~~~~~~~
 - //
 - // Copyright (c) 2003-2019 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_COMPLETION_CONDITION_HPP
 - #define ASIO_COMPLETION_CONDITION_HPP
 - 
 - #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 - # pragma once
 - #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 - 
 - #include "asio/detail/config.hpp"
 - #include <cstddef>
 - 
 - #include "asio/detail/push_options.hpp"
 - 
 - namespace asio {
 - 
 - namespace detail {
 - 
 - // The default maximum number of bytes to transfer in a single operation.
 - enum default_max_transfer_size_t { default_max_transfer_size = 65536 };
 - 
 - // Adapt result of old-style completion conditions (which had a bool result
 - // where true indicated that the operation was complete).
 - inline std::size_t adapt_completion_condition_result(bool result)
 - {
 -   return result ? 0 : default_max_transfer_size;
 - }
 - 
 - // Adapt result of current completion conditions (which have a size_t result
 - // where 0 means the operation is complete, and otherwise the result is the
 - // maximum number of bytes to transfer on the next underlying operation).
 - inline std::size_t adapt_completion_condition_result(std::size_t result)
 - {
 -   return result;
 - }
 - 
 - class transfer_all_t
 - {
 - public:
 -   typedef std::size_t result_type;
 - 
 -   template <typename Error>
 -   std::size_t operator()(const Error& err, std::size_t)
 -   {
 -     return !!err ? 0 : default_max_transfer_size;
 -   }
 - };
 - 
 - class transfer_at_least_t
 - {
 - public:
 -   typedef std::size_t result_type;
 - 
 -   explicit transfer_at_least_t(std::size_t minimum)
 -     : minimum_(minimum)
 -   {
 -   }
 - 
 -   template <typename Error>
 -   std::size_t operator()(const Error& err, std::size_t bytes_transferred)
 -   {
 -     return (!!err || bytes_transferred >= minimum_)
 -       ? 0 : default_max_transfer_size;
 -   }
 - 
 - private:
 -   std::size_t minimum_;
 - };
 - 
 - class transfer_exactly_t
 - {
 - public:
 -   typedef std::size_t result_type;
 - 
 -   explicit transfer_exactly_t(std::size_t size)
 -     : size_(size)
 -   {
 -   }
 - 
 -   template <typename Error>
 -   std::size_t operator()(const Error& err, std::size_t bytes_transferred)
 -   {
 -     return (!!err || bytes_transferred >= size_) ? 0 :
 -       (size_ - bytes_transferred < default_max_transfer_size
 -         ? size_ - bytes_transferred : std::size_t(default_max_transfer_size));
 -   }
 - 
 - private:
 -   std::size_t size_;
 - };
 - 
 - } // namespace detail
 - 
 - /**
 -  * @defgroup completion_condition Completion Condition Function Objects
 -  *
 -  * Function objects used for determining when a read or write operation should
 -  * complete.
 -  */
 - /*@{*/
 - 
 - /// Return a completion condition function object that indicates that a read or
 - /// write operation should continue until all of the data has been transferred,
 - /// or until an error occurs.
 - /**
 -  * This function is used to create an object, of unspecified type, that meets
 -  * CompletionCondition requirements.
 -  *
 -  * @par Example
 -  * Reading until a buffer is full:
 -  * @code
 -  * boost::array<char, 128> buf;
 -  * asio::error_code ec;
 -  * std::size_t n = asio::read(
 -  *     sock, asio::buffer(buf),
 -  *     asio::transfer_all(), ec);
 -  * if (ec)
 -  * {
 -  *   // An error occurred.
 -  * }
 -  * else
 -  * {
 -  *   // n == 128
 -  * }
 -  * @endcode
 -  */
 - #if defined(GENERATING_DOCUMENTATION)
 - unspecified transfer_all();
 - #else
 - inline detail::transfer_all_t transfer_all()
 - {
 -   return detail::transfer_all_t();
 - }
 - #endif
 - 
 - /// Return a completion condition function object that indicates that a read or
 - /// write operation should continue until a minimum number of bytes has been
 - /// transferred, or until an error occurs.
 - /**
 -  * This function is used to create an object, of unspecified type, that meets
 -  * CompletionCondition requirements.
 -  *
 -  * @par Example
 -  * Reading until a buffer is full or contains at least 64 bytes:
 -  * @code
 -  * boost::array<char, 128> buf;
 -  * asio::error_code ec;
 -  * std::size_t n = asio::read(
 -  *     sock, asio::buffer(buf),
 -  *     asio::transfer_at_least(64), ec);
 -  * if (ec)
 -  * {
 -  *   // An error occurred.
 -  * }
 -  * else
 -  * {
 -  *   // n >= 64 && n <= 128
 -  * }
 -  * @endcode
 -  */
 - #if defined(GENERATING_DOCUMENTATION)
 - unspecified transfer_at_least(std::size_t minimum);
 - #else
 - inline detail::transfer_at_least_t transfer_at_least(std::size_t minimum)
 - {
 -   return detail::transfer_at_least_t(minimum);
 - }
 - #endif
 - 
 - /// Return a completion condition function object that indicates that a read or
 - /// write operation should continue until an exact number of bytes has been
 - /// transferred, or until an error occurs.
 - /**
 -  * This function is used to create an object, of unspecified type, that meets
 -  * CompletionCondition requirements.
 -  *
 -  * @par Example
 -  * Reading until a buffer is full or contains exactly 64 bytes:
 -  * @code
 -  * boost::array<char, 128> buf;
 -  * asio::error_code ec;
 -  * std::size_t n = asio::read(
 -  *     sock, asio::buffer(buf),
 -  *     asio::transfer_exactly(64), ec);
 -  * if (ec)
 -  * {
 -  *   // An error occurred.
 -  * }
 -  * else
 -  * {
 -  *   // n == 64
 -  * }
 -  * @endcode
 -  */
 - #if defined(GENERATING_DOCUMENTATION)
 - unspecified transfer_exactly(std::size_t size);
 - #else
 - inline detail::transfer_exactly_t transfer_exactly(std::size_t size)
 - {
 -   return detail::transfer_exactly_t(size);
 - }
 - #endif
 - 
 - /*@}*/
 - 
 - } // namespace asio
 - 
 - #include "asio/detail/pop_options.hpp"
 - 
 - #endif // ASIO_COMPLETION_CONDITION_HPP
 
 
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