One or more buffers into which the data will be received. Although the buffers object may be copied as necessary, ownership of the underlying memory blocks is retained by the caller, which must guarantee that they remain valid until the completion handler is called.

An endpoint object that receives the endpoint of the remote sender of the data. Ownership of the sender_endpoint object is retained by the caller, which must guarantee that it is valid until the completion handler is called.

Flags specifying how the receive call is to be made.

The completion token that will be used to produce a completion handler, which will be called when the receive completes. Potential completion tokens include use_future, use_awaitable, yield_context, or a function object with the correct completion signature. The function signature of the completion handler must be:

void handler(
  const asio::error_code& error, // Result of operation.
  std::size_t bytes_transferred // Number of bytes received.
);

Regardless of whether the asynchronous operation completes immediately or not, the completion handler will not be invoked from within this function. On immediate completion, invocation of the handler will be performed in a manner equivalent to using post.