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basic_random_access_file::write_some_at (1 of 2 overloads)

Write some data to the handle at the specified offset.

    typename ConstBufferSequence>
std::size_t write_some_at(
    uint64_t offset,
    const ConstBufferSequence & buffers);

This function is used to write data to the random-access handle. The function call will block until one or more bytes of the data has been written successfully, or until an error occurs.



The offset at which the data will be written.


One or more data buffers to be written to the handle.

Return Value

The number of bytes written.



Thrown on failure. An error code of boost::asio::error::eof indicates that the end of the file was reached.


The write_some_at operation may not write all of the data. Consider using the write_at function if you need to ensure that all data is written before the blocking operation completes.


To write a single data buffer use the buffer function as follows:

handle.write_some_at(42, boost::asio::buffer(data, size));

See the buffer documentation for information on writing multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.