On Friday, July 11, 2014 4:17:49 PM UTC-4, Job van der Zwan wrote:
>
> So this is an offtopic question inspired by the talk: around the 57th
> minute in the second video there's a discussion about + and +=. Although I
> didn't hear the question, I assume it was equal to mine: if we had a
> separate += operator, then *a += b* could be defined to update the fields
> of a, whereas *a = a + b* requires the creation of a new object. Since
> "don't generate garbage in the first place" is a good form of memory
> optimisation in *any *garbage collected language, that sounds like quite
> a legit use-case to me, especially in a language dedicated to number
> crunching.
>
See the discussion in:
https://github.com/JuliaLang/julia/issues/249
https://github.com/JuliaLang/julia/issues/7052
As discussed in #249, this change would make it much harder to write
generic code, because the meaning of += could change drastically depending
upon the types. As discussed in #7052, this doesn't seem like it will help
much in real applications, because real applications tend to be more
complicated than a += b, and instead tend to have things like a += 4b - 3c
+ 2d.^2.
