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Get a list of buffers that represents the output sequence, with the given size.

mutable_buffers_type prepare(
    std::size_t n);

Ensures that the output sequence can accommodate n characters, reallocating character array objects as necessary.

Return Value

An object of type mutable_buffers_type that satisfies MutableBufferSequence requirements, representing character array objects at the start of the output sequence such that the sum of the buffer sizes is n.



If size() + n > max_size().


The returned object is invalidated by any basic_streambuf member function that modifies the input sequence or output sequence.