slice

        # IO::Buffer.slice

(from ruby core)
### Implementation from Buffer
---
    slice(offset, length) -> io_buffer

---

Produce another IO::Buffer which is a slice (or view into) the current
one starting at `offset` bytes and going for `length` bytes.

The slicing happens without copying of memory, and the slice keeps being
associated with the original buffer's source (string, or file), if any.

Raises RuntimeError if the <tt>offset+length<tt> is out of the current
buffer's bounds.

    string = 'test'
    buffer = IO::Buffer.for(string)

    slice = buffer.slice(1, 2)
    # =>
    #  #<IO::Buffer 0x00007fc3d34ebc49+2 SLICE>
    #  0x00000000  65 73                                           es

    # Put "o" into 0s position of the slice
    slice.set_string('o', 0)
    slice
    # =>
    #  #<IO::Buffer 0x00007fc3d34ebc49+2 SLICE>
    #  0x00000000  6f 73                                           os

    # it is also visible at position 1 of the original buffer
    buffer
    # =>
    #  #<IO::Buffer 0x00007fc3d31e2d80+4 SLICE>
    #  0x00000000  74 6f 73 74                                     tost

    # ...and original string
    string
    # => tost