boost/asio/impl/write_at.hpp
// // impl/write_at.hpp // ~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2012 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 BOOST_ASIO_IMPL_WRITE_AT_HPP #define BOOST_ASIO_IMPL_WRITE_AT_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include <boost/asio/buffer.hpp> #include <boost/asio/completion_condition.hpp> #include <boost/asio/detail/array_fwd.hpp> #include <boost/asio/detail/base_from_completion_cond.hpp> #include <boost/asio/detail/bind_handler.hpp> #include <boost/asio/detail/consuming_buffers.hpp> #include <boost/asio/detail/dependent_type.hpp> #include <boost/asio/detail/handler_alloc_helpers.hpp> #include <boost/asio/detail/handler_invoke_helpers.hpp> #include <boost/asio/detail/handler_type_requirements.hpp> #include <boost/asio/detail/throw_error.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition> std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, boost::system::error_code& ec) { ec = boost::system::error_code(); boost::asio::detail::consuming_buffers< const_buffer, ConstBufferSequence> tmp(buffers); std::size_t total_transferred = 0; tmp.prepare(detail::adapt_completion_condition_result( completion_condition(ec, total_transferred))); while (tmp.begin() != tmp.end()) { std::size_t bytes_transferred = d.write_some_at( offset + total_transferred, tmp, ec); tmp.consume(bytes_transferred); total_transferred += bytes_transferred; tmp.prepare(detail::adapt_completion_condition_result( completion_condition(ec, total_transferred))); } return total_transferred; } template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers) { boost::system::error_code ec; std::size_t bytes_transferred = write_at( d, offset, buffers, transfer_all(), ec); boost::asio::detail::throw_error(ec, "write_at"); return bytes_transferred; } template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, boost::system::error_code& ec) { return write_at(d, offset, buffers, transfer_all(), ec); } template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition) { boost::system::error_code ec; std::size_t bytes_transferred = write_at( d, offset, buffers, completion_condition, ec); boost::asio::detail::throw_error(ec, "write_at"); return bytes_transferred; } #if !defined(BOOST_NO_IOSTREAM) template <typename SyncRandomAccessWriteDevice, typename Allocator, typename CompletionCondition> std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, CompletionCondition completion_condition, boost::system::error_code& ec) { std::size_t bytes_transferred = write_at( d, offset, b.data(), completion_condition, ec); b.consume(bytes_transferred); return bytes_transferred; } template <typename SyncRandomAccessWriteDevice, typename Allocator> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b) { boost::system::error_code ec; std::size_t bytes_transferred = write_at(d, offset, b, transfer_all(), ec); boost::asio::detail::throw_error(ec, "write_at"); return bytes_transferred; } template <typename SyncRandomAccessWriteDevice, typename Allocator> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, boost::system::error_code& ec) { return write_at(d, offset, b, transfer_all(), ec); } template <typename SyncRandomAccessWriteDevice, typename Allocator, typename CompletionCondition> inline std::size_t write_at(SyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, CompletionCondition completion_condition) { boost::system::error_code ec; std::size_t bytes_transferred = write_at( d, offset, b, completion_condition, ec); boost::asio::detail::throw_error(ec, "write_at"); return bytes_transferred; } #endif // !defined(BOOST_NO_IOSTREAM) namespace detail { template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> class write_at_op : detail::base_from_completion_cond<CompletionCondition> { public: write_at_op(AsyncRandomAccessWriteDevice& device, boost::uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, WriteHandler& handler) : detail::base_from_completion_cond< CompletionCondition>(completion_condition), device_(device), offset_(offset), buffers_(buffers), total_transferred_(0), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_op(const write_at_op& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(other.handler_) { } write_at_op(write_at_op&& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, std::size_t bytes_transferred, int start = 0) { switch (start) { case 1: buffers_.prepare(this->check_for_completion(ec, total_transferred_)); for (;;) { device_.async_write_some_at( offset_ + total_transferred_, buffers_, BOOST_ASIO_MOVE_CAST(write_at_op)(*this)); return; default: total_transferred_ += bytes_transferred; buffers_.consume(bytes_transferred); buffers_.prepare(this->check_for_completion(ec, total_transferred_)); if ((!ec && bytes_transferred == 0) || buffers_.begin() == buffers_.end()) break; } handler_(ec, static_cast<const std::size_t&>(total_transferred_)); } } //private: AsyncRandomAccessWriteDevice& device_; boost::uint64_t offset_; boost::asio::detail::consuming_buffers< const_buffer, ConstBufferSequence> buffers_; std::size_t total_transferred_; WriteHandler handler_; }; template <typename AsyncRandomAccessWriteDevice, typename CompletionCondition, typename WriteHandler> class write_at_op<AsyncRandomAccessWriteDevice, boost::asio::mutable_buffers_1, CompletionCondition, WriteHandler> : detail::base_from_completion_cond<CompletionCondition> { public: write_at_op(AsyncRandomAccessWriteDevice& device, boost::uint64_t offset, const boost::asio::mutable_buffers_1& buffers, CompletionCondition completion_condition, WriteHandler& handler) : detail::base_from_completion_cond< CompletionCondition>(completion_condition), device_(device), offset_(offset), buffer_(buffers), total_transferred_(0), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_op(const write_at_op& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffer_(other.buffer_), total_transferred_(other.total_transferred_), handler_(other.handler_) { } write_at_op(write_at_op&& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffer_(other.buffer_), total_transferred_(other.total_transferred_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, std::size_t bytes_transferred, int start = 0) { std::size_t n = 0; switch (start) { case 1: n = this->check_for_completion(ec, total_transferred_); for (;;) { device_.async_write_some_at(offset_ + total_transferred_, boost::asio::buffer(buffer_ + total_transferred_, n), BOOST_ASIO_MOVE_CAST(write_at_op)(*this)); return; default: total_transferred_ += bytes_transferred; if ((!ec && bytes_transferred == 0) || (n = this->check_for_completion(ec, total_transferred_)) == 0 || total_transferred_ == boost::asio::buffer_size(buffer_)) break; } handler_(ec, static_cast<const std::size_t&>(total_transferred_)); } } //private: AsyncRandomAccessWriteDevice& device_; boost::uint64_t offset_; boost::asio::mutable_buffer buffer_; std::size_t total_transferred_; WriteHandler handler_; }; template <typename AsyncRandomAccessWriteDevice, typename CompletionCondition, typename WriteHandler> class write_at_op<AsyncRandomAccessWriteDevice, boost::asio::const_buffers_1, CompletionCondition, WriteHandler> : detail::base_from_completion_cond<CompletionCondition> { public: write_at_op(AsyncRandomAccessWriteDevice& device, boost::uint64_t offset, const boost::asio::const_buffers_1& buffers, CompletionCondition completion_condition, WriteHandler& handler) : detail::base_from_completion_cond< CompletionCondition>(completion_condition), device_(device), offset_(offset), buffer_(buffers), total_transferred_(0), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_op(const write_at_op& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffer_(other.buffer_), total_transferred_(other.total_transferred_), handler_(other.handler_) { } write_at_op(write_at_op&& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffer_(other.buffer_), total_transferred_(other.total_transferred_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, std::size_t bytes_transferred, int start = 0) { std::size_t n = 0; switch (start) { case 1: n = this->check_for_completion(ec, total_transferred_); for (;;) { device_.async_write_some_at(offset_ + total_transferred_, boost::asio::buffer(buffer_ + total_transferred_, n), BOOST_ASIO_MOVE_CAST(write_at_op)(*this)); return; default: total_transferred_ += bytes_transferred; if ((!ec && bytes_transferred == 0) || (n = this->check_for_completion(ec, total_transferred_)) == 0 || total_transferred_ == boost::asio::buffer_size(buffer_)) break; } handler_(ec, static_cast<const std::size_t&>(total_transferred_)); } } //private: AsyncRandomAccessWriteDevice& device_; boost::uint64_t offset_; boost::asio::const_buffer buffer_; std::size_t total_transferred_; WriteHandler handler_; }; template <typename AsyncRandomAccessWriteDevice, typename Elem, typename CompletionCondition, typename WriteHandler> class write_at_op<AsyncRandomAccessWriteDevice, boost::array<Elem, 2>, CompletionCondition, WriteHandler> : detail::base_from_completion_cond<CompletionCondition> { public: write_at_op(AsyncRandomAccessWriteDevice& device, boost::uint64_t offset, const boost::array<Elem, 2>& buffers, CompletionCondition completion_condition, WriteHandler& handler) : detail::base_from_completion_cond< CompletionCondition>(completion_condition), device_(device), offset_(offset), buffers_(buffers), total_transferred_(0), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_op(const write_at_op& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(other.handler_) { } write_at_op(write_at_op&& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, std::size_t bytes_transferred, int start = 0) { typename boost::asio::detail::dependent_type<Elem, boost::array<boost::asio::const_buffer, 2> >::type bufs = {{ boost::asio::const_buffer(buffers_[0]), boost::asio::const_buffer(buffers_[1]) }}; std::size_t buffer_size0 = boost::asio::buffer_size(bufs[0]); std::size_t buffer_size1 = boost::asio::buffer_size(bufs[1]); std::size_t n = 0; switch (start) { case 1: n = this->check_for_completion(ec, total_transferred_); for (;;) { bufs[0] = boost::asio::buffer(bufs[0] + total_transferred_, n); bufs[1] = boost::asio::buffer( bufs[1] + (total_transferred_ < buffer_size0 ? 0 : total_transferred_ - buffer_size0), n - boost::asio::buffer_size(bufs[0])); device_.async_write_some_at(offset_ + total_transferred_, bufs, BOOST_ASIO_MOVE_CAST(write_at_op)(*this)); return; default: total_transferred_ += bytes_transferred; if ((!ec && bytes_transferred == 0) || (n = this->check_for_completion(ec, total_transferred_)) == 0 || total_transferred_ == buffer_size0 + buffer_size1) break; } handler_(ec, static_cast<const std::size_t&>(total_transferred_)); } } //private: AsyncRandomAccessWriteDevice& device_; boost::uint64_t offset_; boost::array<Elem, 2> buffers_; std::size_t total_transferred_; WriteHandler handler_; }; #if defined(BOOST_ASIO_HAS_STD_ARRAY) template <typename AsyncRandomAccessWriteDevice, typename Elem, typename CompletionCondition, typename WriteHandler> class write_at_op<AsyncRandomAccessWriteDevice, std::array<Elem, 2>, CompletionCondition, WriteHandler> : detail::base_from_completion_cond<CompletionCondition> { public: write_at_op(AsyncRandomAccessWriteDevice& device, boost::uint64_t offset, const std::array<Elem, 2>& buffers, CompletionCondition completion_condition, WriteHandler& handler) : detail::base_from_completion_cond< CompletionCondition>(completion_condition), device_(device), offset_(offset), buffers_(buffers), total_transferred_(0), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_op(const write_at_op& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(other.handler_) { } write_at_op(write_at_op&& other) : detail::base_from_completion_cond<CompletionCondition>(other), device_(other.device_), offset_(other.offset_), buffers_(other.buffers_), total_transferred_(other.total_transferred_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, std::size_t bytes_transferred, int start = 0) { typename boost::asio::detail::dependent_type<Elem, std::array<boost::asio::const_buffer, 2> >::type bufs = {{ boost::asio::const_buffer(buffers_[0]), boost::asio::const_buffer(buffers_[1]) }}; std::size_t buffer_size0 = boost::asio::buffer_size(bufs[0]); std::size_t buffer_size1 = boost::asio::buffer_size(bufs[1]); std::size_t n = 0; switch (start) { case 1: n = this->check_for_completion(ec, total_transferred_); for (;;) { bufs[0] = boost::asio::buffer(bufs[0] + total_transferred_, n); bufs[1] = boost::asio::buffer( bufs[1] + (total_transferred_ < buffer_size0 ? 0 : total_transferred_ - buffer_size0), n - boost::asio::buffer_size(bufs[0])); device_.async_write_some_at(offset_ + total_transferred_, bufs, BOOST_ASIO_MOVE_CAST(write_at_op)(*this)); return; default: total_transferred_ += bytes_transferred; if ((!ec && bytes_transferred == 0) || (n = this->check_for_completion(ec, total_transferred_)) == 0 || total_transferred_ == buffer_size0 + buffer_size1) break; } handler_(ec, static_cast<const std::size_t&>(total_transferred_)); } } //private: AsyncRandomAccessWriteDevice& device_; boost::uint64_t offset_; std::array<Elem, 2> buffers_; std::size_t total_transferred_; WriteHandler handler_; }; #endif // defined(BOOST_ASIO_HAS_STD_ARRAY) template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline void* asio_handler_allocate(std::size_t size, write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler>* this_handler) { return boost_asio_handler_alloc_helpers::allocate( size, this_handler->handler_); } template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline void asio_handler_deallocate(void* pointer, std::size_t size, write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler>* this_handler) { boost_asio_handler_alloc_helpers::deallocate( pointer, size, this_handler->handler_); } template <typename Function, typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline void asio_handler_invoke(Function& function, write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler>* this_handler) { boost_asio_handler_invoke_helpers::invoke( function, this_handler->handler_); } template <typename Function, typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline void asio_handler_invoke(const Function& function, write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler>* this_handler) { boost_asio_handler_invoke_helpers::invoke( function, this_handler->handler_); } template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler> make_write_at_op(AsyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, WriteHandler handler) { return write_at_op<AsyncRandomAccessWriteDevice, ConstBufferSequence, CompletionCondition, WriteHandler>( d, offset, buffers, completion_condition, handler); } } // namespace detail template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename CompletionCondition, typename WriteHandler> inline void async_write_at(AsyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, BOOST_ASIO_MOVE_ARG(WriteHandler) handler) { // If you get an error on the following line it means that your handler does // not meet the documented type requirements for a WriteHandler. BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check; detail::make_write_at_op( d, offset, buffers, completion_condition, BOOST_ASIO_MOVE_CAST(WriteHandler)(handler))( boost::system::error_code(), 0, 1); } template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence, typename WriteHandler> inline void async_write_at(AsyncRandomAccessWriteDevice& d, boost::uint64_t offset, const ConstBufferSequence& buffers, BOOST_ASIO_MOVE_ARG(WriteHandler) handler) { // If you get an error on the following line it means that your handler does // not meet the documented type requirements for a WriteHandler. BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check; detail::make_write_at_op( d, offset, buffers, transfer_all(), BOOST_ASIO_MOVE_CAST(WriteHandler)(handler))( boost::system::error_code(), 0, 1); } #if !defined(BOOST_NO_IOSTREAM) namespace detail { template <typename Allocator, typename WriteHandler> class write_at_streambuf_op { public: write_at_streambuf_op( boost::asio::basic_streambuf<Allocator>& streambuf, WriteHandler& handler) : streambuf_(streambuf), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)) { } #if defined(BOOST_ASIO_HAS_MOVE) write_at_streambuf_op(const write_at_streambuf_op& other) : streambuf_(other.streambuf_), handler_(other.handler_) { } write_at_streambuf_op(write_at_streambuf_op&& other) : streambuf_(other.streambuf_), handler_(BOOST_ASIO_MOVE_CAST(WriteHandler)(other.handler_)) { } #endif // defined(BOOST_ASIO_HAS_MOVE) void operator()(const boost::system::error_code& ec, const std::size_t bytes_transferred) { streambuf_.consume(bytes_transferred); handler_(ec, bytes_transferred); } //private: boost::asio::basic_streambuf<Allocator>& streambuf_; WriteHandler handler_; }; template <typename Allocator, typename WriteHandler> inline void* asio_handler_allocate(std::size_t size, write_at_streambuf_op<Allocator, WriteHandler>* this_handler) { return boost_asio_handler_alloc_helpers::allocate( size, this_handler->handler_); } template <typename Allocator, typename WriteHandler> inline void asio_handler_deallocate(void* pointer, std::size_t size, write_at_streambuf_op<Allocator, WriteHandler>* this_handler) { boost_asio_handler_alloc_helpers::deallocate( pointer, size, this_handler->handler_); } template <typename Function, typename Allocator, typename WriteHandler> inline void asio_handler_invoke(Function& function, write_at_streambuf_op<Allocator, WriteHandler>* this_handler) { boost_asio_handler_invoke_helpers::invoke( function, this_handler->handler_); } template <typename Function, typename Allocator, typename WriteHandler> inline void asio_handler_invoke(const Function& function, write_at_streambuf_op<Allocator, WriteHandler>* this_handler) { boost_asio_handler_invoke_helpers::invoke( function, this_handler->handler_); } template <typename Allocator, typename WriteHandler> inline write_at_streambuf_op<Allocator, WriteHandler> make_write_at_streambuf_op( boost::asio::basic_streambuf<Allocator>& b, WriteHandler handler) { return write_at_streambuf_op<Allocator, WriteHandler>(b, handler); } } // namespace detail template <typename AsyncRandomAccessWriteDevice, typename Allocator, typename CompletionCondition, typename WriteHandler> inline void async_write_at(AsyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, CompletionCondition completion_condition, BOOST_ASIO_MOVE_ARG(WriteHandler) handler) { // If you get an error on the following line it means that your handler does // not meet the documented type requirements for a WriteHandler. BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check; async_write_at(d, offset, b.data(), completion_condition, detail::make_write_at_streambuf_op( b, BOOST_ASIO_MOVE_CAST(WriteHandler)(handler))); } template <typename AsyncRandomAccessWriteDevice, typename Allocator, typename WriteHandler> inline void async_write_at(AsyncRandomAccessWriteDevice& d, boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, BOOST_ASIO_MOVE_ARG(WriteHandler) handler) { // If you get an error on the following line it means that your handler does // not meet the documented type requirements for a WriteHandler. BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check; async_write_at(d, offset, b.data(), transfer_all(), detail::make_write_at_streambuf_op( b, BOOST_ASIO_MOVE_CAST(WriteHandler)(handler))); } #endif // !defined(BOOST_NO_IOSTREAM) } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #endif // BOOST_ASIO_IMPL_WRITE_AT_HPP