There is something about this immutability thing I really don't like. In the authors example it looks like v1[0] is set to 42 (const auto v2 = v1.set(0, 42)), at least that's how you read it because it contains the word 'set', but you have to 'know' that v1 is immutable and is actually not setting the value, but returning it. So IMAO the naming should be better, I like to read code that is not confusing.
If this construct, that I actually never needed in my entire career, is handy for undo/redo, why not just have a dead simple undo stack? In what situation is an immutable structure your best choice?
If this construct, that I actually never needed in my entire career, is handy for undo/redo, why not just have a dead simple undo stack? In what situation is an immutable structure your best choice?