If you have a large array named `foo` (let's say i...

# language-proposals

[benleggiero]

If you have a large array named foo (let's say it's 1GB) and then you say var bar = foo, a "copy" is made, yes. And I'm not 100% sure how, but no delay is incurred. I suspect that you get a new pointer, and any changes you make are reflected as diffs.

Also, let foo = "foo"; let bar = foo, IIRC, makes foo and bar point to the same memory, which is safe because neither can be mutated.

[voddan]

Unfortunately, there are no diffs. That would be like a Git inside an array.

[voddan]

Swift copies lazily. On var bar = foo nothing happens until you mutate bar. Then the whole 1GB is copied.

[voddan]

I admit I have a very strong negative opinion of this part of Swift. Sorry if I sound bitter