basic_random_access_file::write_some

basic_random_access_file::write_some_at (1 of 2 overloads)

Write some data to the handle at the specified offset.

template<
    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.

Parameters

offset: The offset at which the data will be written.
buffers: One or more data buffers to be written to the handle.

Return Value

The number of bytes written.

Exceptions

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

Remarks

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.

Example

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

handle.write_some_at(42, 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.