alt Hacker NewsI'm pretty interested in realtime computing and didn't realise C++ was considered bandwidth efficient! Coming from C, I find myself avoiding most 'new' C++ features because I can't easily figure out how they allocate without grabbing a memory profiler.
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C++ is like C with extra features, but you don't need to use them.
If you want control over your memory, you can do pointers the C way, but you still have features like templates, namespaces, etc... Another advantage of C++ is that it can go both high and low level within the same language.
Disadvantage of C++ is mostly related to portability and interop. Things like name mangling, constructors, etc... can be a problem. Also, C++ officially doesn't support some C features like "restrict". In practice, you often can use them, but it is nonstandard. Probably not a concern for HPC.
C++ comes with baggage and requires up-front training. You need to dive into every language feature and STL library, learn how compilers implement stuff, then decide what to use and what not to, and the decision often depends on context. It has a high cognitive load in my opinion for that reason. But once you do that, you get a relatively high-level language that can go as low and be as fast as C.
I don't think there's much difference between C and C++ (and Rust, etc...) when it comes to this.
> realtime computing
Even with HDL defined accelerators, that statement may not mean what people assume. =3
https://en.wikipedia.org/wiki/Latency_(engineering)
https://en.wikipedia.org/wiki/Clock_domain_crossing
https://en.wikipedia.org/wiki/Metastability_(electronics)
https://en.wikipedia.org/wiki/The_Power_of_10:_Rules_for_Dev...
You can always go through cachegrind or perf and see what happens with your code.
I managed to reach practical IPC limits of the hardware I was running on, and while I could theoretically make prefetcher happier with some matrix reordering, looking back, I'm not sure how much performance it provided since the FPU was already saturated at that point.