Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by pjmlp on Wednesday August 05, 2020 @11:26AM
(#24061865)
Rust also has operator overloading and implicit conversations, both can cause memory allocations.
Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by cogman10 on Wednesday August 05, 2020 @12:02PM
(#24062305)
Certainly. However, both of those things (from what I've seen) are fairly rare.
The C++ copy constructor comes up fairly frequently.
Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by pjmlp on Wednesday August 05, 2020 @12:10PM
(#24062395)
Like unsafe Rust code, there is the theory and then there are the code bases that one finds out in the wild on crates.io and in-house, not necessarily using best practices.
Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by dthul on Wednesday August 05, 2020 @05:35PM
(#24065895)
Rust does not have implicit type conversions.
Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by pjmlp on Thursday August 06, 2020 @02:07AM
(#24068509)
Via Deref.
Re:Sub-10 ms Latency in Java: Concurrent GC with Green Threads
by dthul on Thursday August 06, 2020 @02:53AM
(#24068711)
Not in practice. It's only used for reference coercions to existing objects.
You would need to ignore the documentation and bend over backwards to use it for an actual type conversion, because you can only return references.
There are a few places in C++ where allocation can happen pretty much invisibly. A copy constructor is an example of that. You might see a new allocation simply by calling a method.
With rust, you usually won't see an allocation unless it is explicitly called for. You can follow the call tree and very easily pick out when those allocations are happening.