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
bytes,
resizing the basic_string object as necessary.
An object of type mutable_buffers_type
that satisfies MutableBufferSequence
requirements, representing basic_string memory at the start of the output
sequence of size n
.
If size() + n > max_size()
.
The returned object is invalidated by any dynamic_string_buffer
or basic_string
member function that modifies the input sequence
or output sequence.