IO::Buffer#~

static VALUE
io_buffer_not(VALUE self)
{
    struct rb_io_buffer_view *buffer = get_io_buffer_view(self);

    const void *base;
    size_t size;
    io_buffer_get_bytes_for_reading(buffer, &base, &size);

    VALUE output = rb_io_buffer_new(NULL, size, io_flags_for_size(size));
    struct rb_io_buffer_view *output_buffer = get_io_buffer_view(output);

    memory_not(output_buffer->base, base, size);

    return output;
}