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Sure, ARC is a form of very specific, constrained garbage collection. Compile-time, reference-counting GC, not runtime tracing GC. So no background collector,
by andsoitis 11mo ago
Sure, ARC is a form of very specific, constrained garbage collection.
Compile-time, reference-counting GC, not runtime tracing GC. So no background collector, no heap tracing, and no stop-the-world pauses. Very different from the JVM, .Net, or Go.
- pjmlp 11mo agoReference counting is a GC algorithm from CS point of view, it doesn't matter if it is compile time or runtime. Additionally there isn't a single ARC implementation that is 100% compile time, that when looking at the generated machine code has removed all occurrences from RC machinery.
- Warwolt 11mo agoBut common, collouqialy "Garbage Collection" as a language feature refers to a run time garbage collector. Saying that the language has GC just because it has opt-in reference counting is needlessly pedantic
- pjmlp 11mo agoKnowlege gets taught in specific institutions exactly because street knowledge is quite often incorrect, like in this case, spreading urban myths based in shaky foundations.
- gf000 11mo agoWhile I am usually the one that also goes in and correct people incorrectly calling RC not a GC, the important distinction here is that Rust (and C++) has the necessary language constructs to be able to implement ref counting entirely as a library.
- pjmlp 11mo agoWhich is a performance bottleneck, as the compiler is blind to library implementations and cannot optimise accordingly. Also implementation has nothing to do with CS definition, there are tracing GC libraries for C as well.