template<class AsyncReadStream, class MutableBufferSequence, class CompletionToken>
DEDUCED async_read(AsyncReadStream& stream,
const MutableBufferSequence& buffers,
CompletionToken&& token);
template<class AsyncReadStream, class MutableBufferSequence, class CompletionCondition,
class CompletionToken>
DEDUCED async_read(AsyncReadStream& stream,
const MutableBufferSequence& buffers,
CompletionCondition completion_condition,
CompletionToken&& token);
A composed asynchronous read operation ([async.reqmts.async.composed], [buffer.reqmts.read.write]).
Completion signature: void(error_code ec, size_t n).
Effects: Reads data from the buffer-oriented asynchronous read stream ([buffer.stream.reqmts.asyncreadstream]) object stream by invoking the stream's async_read_some member function (henceforth referred to as asynchronous read_some operations) zero or more times.
The completion_condition parameter specifies a completion condition to be called prior to each asynchronous read_some operation. The completion condition is passed the error_code value from the most recent asynchronous read_some operation, and the total number of bytes transferred in the asynchronous read operation so far. The completion condition return value specifies the maximum number of bytes to be read on the subsequent asynchronous read_some operation. Overloads where a completion condition is not specified behave as if called with an object of class transfer_all.
The program shall ensure the AsyncReadStream object stream is valid until the completion handler for the asynchronous operation is invoked.
On completion of the asynchronous operation, ec is the error_code value from the most recent asynchronous read_some operation, and n is the total number of bytes transferred.
Remarks: This function shall not participate in overload resolution unless is_mutable_buffer_sequence_v<MutableBufferSequence> is true.
template<class AsyncReadStream, class DynamicBuffer, class CompletionToken>
DEDUCED async_read(AsyncReadStream& stream,
DynamicBuffer&& b, CompletionToken&& token);
template<class AsyncReadStream, class DynamicBuffer, class CompletionCondition,
class CompletionToken>
DEDUCED async_read(AsyncReadStream& stream,
DynamicBuffer&& b,
CompletionCondition completion_condition,
CompletionToken&& token);
Completion signature: void(error_code ec, size_t n).
Effects: Initiates an asynchronous operation to read data from the buffer-oriented asynchronous read stream ([buffer.stream.reqmts.asyncreadstream]) object stream by performing one or more asynchronous read_some operations on the stream.
Data is placed into the dynamic buffer ([buffer.reqmts.dynamicbuffer]) object b. A mutable buffer sequence ([buffer.reqmts.mutablebuffersequence]) is obtained prior to each async_read_some call using b.prepare(N), where N is an unspecified value such that N is less than or equal to b.max_size() - b.size(). [ Note: Implementations can use b.capacity() when determining N, to minimize the number of asynchronous read_some operations performed on the stream. — end note ] After the completion of each asynchronous read_some operation, the implementation performs b.commit(n), where n is the value passed to the asynchronous read_some operation's completion handler.
The completion_condition parameter specifies a completion condition to be called prior to each asynchronous read_some operation. The completion condition is passed the error_code value from the most recent asynchronous read_some operation, and the total number of bytes transferred in the asynchronous read operation so far. The completion condition return value specifies the maximum number of bytes to be read on the subsequent asynchronous read_some operation. Overloads where a completion condition is not specified behave as if called with an object of class transfer_all.
The program shall ensure the AsyncReadStream object stream is valid until the completion handler for the asynchronous operation is invoked.
On completion of the asynchronous operation, ec is the error_code value from the most recent asynchronous read_some operation, and n is the total number of bytes transferred.
Remarks: This function shall not participate in overload resolution unless is_dynamic_buffer_v<DynamicBuffer> is true.