Write all of the supplied data at the specified offset before returning.
template< typename SyncRandomAccessWriteDevice, typename Allocator> std::size_t write_at( SyncRandomAccessWriteDevice & d, uint64_t offset, basic_streambuf< Allocator > & b);
This function is used to write a certain number of bytes of data to a random access device at a specified offset. The call will block until one of the following conditions is true:
basic_streambufhas been written.
This operation is implemented in terms of zero or more calls to the device's write_some_at function.
The device to which the data is to be written. The type must support the SyncRandomAccessWriteDevice concept.
The offset at which the data will be written.
object from which data will be written.
The number of bytes transferred.
Thrown on failure.
This overload is equivalent to calling:
boost::asio::write_at( d, 42, b, boost::asio::transfer_all());