Beware of the following code. It doesn’t do what you think:
clones[cloning] = &(*cloning)
Your references won’t change.
2022/03/17 21:46:17 self: 0xc0000661e0 parent: 0x0
2022/03/17 21:46:17 left: 0x0 right: 0x0
2022/03/17 21:46:17 first: 0xc000066230 last: 0xc000066230
2022/03/17 21:46:17
2022/03/17 21:46:17 self: 0xc0000661e0 parent: 0x0
2022/03/17 21:46:17 left: 0x0 right: 0x0
2022/03/17 21:46:17 first: 0xc000066230 last: 0xc000066230
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I believe this is because the compiler optimizes away your cleverness as being unnecessary redundancy.
To get what you probably want (a clone) you need to use and explicit assignment to force it to create a copy before taking a reference to that copy:
c := *cloning
clones[cloning] = &c
This looks better:
2022/03/17 21:40:14 self: 0xc0000661e0 parent: 0x0
2022/03/17 21:40:14 left: 0x0 right: 0x0
2022/03/17 21:40:14 first: 0xc000066230 last: 0xc000066230
2022/03/17 21:40:14
2022/03/17 21:40:14 self: 0xc000066280 parent: 0x0
2022/03/17 21:40:14 left: 0x0 right: 0x0
2022/03/17 21:40:14 first: 0xc0000662d0 last: 0xc0000662d0
By the way, to print references use fmt/log.Printf("%p",ref).
I’ve known about this for a while, but never actually wrote it anywhere. Best to get the word out.
#golang #coding #tips #cloning