Comment by StellarScience

4 hours ago

I liked how the discussion of 'delta = x - y' moved right on to how really you usually want delta = abs(x - y), so let's talk about that instead...

Even beyond Stroustrup, Dijkstra, and Google, this whole panel of C++ luminaries agrees to prefer signed types and explains pretty clearly why:

- 12:12-13:08 - https://www.youtube.com/watch?v=Puio5dly9N8#t=12m12s

- 42:40-45:26 - https://www.youtube.com/watch?v=Puio5dly9N8#t=42m40s

- 1:02:50-1:03:15 - https://www.youtube.com/watch?v=Puio5dly9N8#t=1h2m50s

4 comments

StellarScience

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nazcan  3 hours ago

Thanks for the excerpts! I was trying to understand the reasoning, which seem to just be in the 2nd excerpt:

- The rules of signed/unsigned are complicated and there is too much auto-conversion - does that mean languages that make this more explicit means this is fine? It just seems ideal to have stronger typing. - It is mentioned that you can initialized an unsigned int to "-2" - but that presumably could also be fixed in the language.

I'm trying to separate out which is "don't do this in C/C++" and which is "don't do this in any language".

  • Groxx  3 hours ago

    that argument (and many others) also round to essentially "implicit imprecise integer casting is surprising but we do it anyway" which is... perhaps the actual problem???

    I've made lints for Go that simply disallow implicit number casting, and omfg the (real, occurring but unnoticed) bugs it found. those kinds of lints are trivial to build, you can just stop doing it. forcing visible casts made many of these problematic patterns extremely suspicious at a glance, catching issues at review time far more easily.