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Curious how long you tried to learn rust? I've found C++ much harder to learn (coming from a python/scala) background. Is it just a case of you forgetting how

Curious how long you tried to learn rust? I've found C++ much harder to learn (coming from a python/scala) background. Is it just a case of you forgetting how hard C++ was to learn?

Const-me 3y ago
I have minimal experience with Rust. OTOH, programming C++ for living since 2000, with a few gaps when I used other languages like Obj-C and C#. I agree C++ is very hard to learn if you only have experience with higher-level languages like Python and Scala. I think there’re two reasons for that. C++ is unsafe. There’s no way around this one, it was designed that way, like C or assembly. Still, with modern toolset it’s not terribly bad. Compilers print warnings, BTW I typically ask them to treat warnings as errors to deliberately fail the build. On Windows, a combination of debug build, debug C runtime, and visual studio debugger helps tremendously. Linux compilers have these sanitizers (address, memory, thread, undefined behavior) which are comparable, they too sacrifice runtime speed for diagnostics and debuggability. Another reason, the language itself is very complicated, especially the templates. However, just because something is in the language doesn’t mean it’s a good idea to use it. You don’t need to be familiar with that stuff unless doing something very advanced, like customizing the Eigen C++ library. Don’t follow the patterns found in the standard library: unlike your code, that library has good reasons to use that template BS. If instead of templates you do something else, C++ becomes much easier to use, and most importantly other people will still be able to read and understand your code. Another reason to avoid excessive template metaprogramming, it slows down the compiler, because template-heavy code often needs to be in headers as opposed to cpp files. P.S. If you don’t need extreme levels of performance (defined as “approach the numbers listed in CPU specs”, the numbers are FLOPS or memory bandwidth), and you don’t need the ecosystem too much, consider C# instead of C++. Much faster than Python, often faster than Scala or Java, easy integration with C should you need that (about the same as Rust, much easier than Python or Java), the only downside is these ~100MB of the runtime. The reputation is weird, but technically the language and runtime are pretty good. For example, here’s a C# library which re-implements a subset of ffmpeg and libavcodec C libraries for one particular platform, Linux on Raspberry Pi4: https://github.com/Const-me/Vrmac/tree/master/VrmacVideo https://github.com/Const-me/Vrmac/tree/master/VrmacVideo
- theLiminator 3y ago
  Personally, I use rust for the ability to go as fast as C++ but with far fewer footguns. Not to mention that I personally really enjoy how they made algebraic data types and package management first class. I suspect that if you really spent time learning rust that you'd really appreciate it coming from C++.
  - Const-me 3y ago
    When I just want the ability to go as fast as conventional readable C++, I use C# instead. Compared to conventional C++, C# is typically only slightly worse in terms of performance. C# is safer than Rust, and the usability is IMO an order of magnitude better. Just the compilation speed is already a huge contributing factor. I use C++ for 2 main reasons, integration with other software or libraries, and performance. When I need the performance, I don’t write conventional C++. I implement custom data structures, usually use vector intrinsics, sometimes use other platform intrinsics like BMI2, sometimes implement custom threading strategies on top of OpenMP or other platform-supplied thread pools. Most of these things are impossible or very hard to express in idiomatic safe Rust, which means the language constantly gets in the way. Also, most programs contain both performance critical and performance agnostic pieces. When both pieces have non-trivial complexity, I typically use both C# and C++ for the software. Often the frontend part is in .NET, and the performance-critical backend is in C++ DLL.
    - theLiminator 3y ago
      I believe rust is actually more thread safe than C#, though the other points you made are pretty true.

Curious how long you tried to learn rust? I've found C++ much harder to learn (coming from a python/scala) background. Is it just a case of you forgetting how hard C++ was to learn?

Const-me 3y ago

I have minimal experience with Rust. OTOH, programming C++ for living since 2000, with a few gaps when I used other languages like Obj-C and C#. I agree C++ is very hard to learn if you only have experience with higher-level languages like Python and Scala. I think there’re two reasons for that. C++ is unsafe. There’s no way around this one, it was designed that way, like C or assembly. Still, with modern toolset it’s not terribly bad. Compilers print warnings, BTW I typically ask them to treat warnings as errors to deliberately fail the build. On Windows, a combination of debug build, debug C runtime, and visual studio debugger helps tremendously. Linux compilers have these sanitizers (address, memory, thread, undefined behavior) which are comparable, they too sacrifice runtime speed for diagnostics and debuggability. Another reason, the language itself is very complicated, especially the templates. However, just because something is in the language doesn’t mean it’s a good idea to use it. You don’t need to be familiar with that stuff unless doing something very advanced, like customizing the Eigen C++ library. Don’t follow the patterns found in the standard library: unlike your code, that library has good reasons to use that template BS. If instead of templates you do something else, C++ becomes much easier to use, and most importantly other people will still be able to read and understand your code. Another reason to avoid excessive template metaprogramming, it slows down the compiler, because template-heavy code often needs to be in headers as opposed to cpp files. P.S. If you don’t need extreme levels of performance (defined as “approach the numbers listed in CPU specs”, the numbers are FLOPS or memory bandwidth), and you don’t need the ecosystem too much, consider C# instead of C++. Much faster than Python, often faster than Scala or Java, easy integration with C should you need that (about the same as Rust, much easier than Python or Java), the only downside is these ~100MB of the runtime. The reputation is weird, but technically the language and runtime are pretty good. For example, here’s a C# library which re-implements a subset of ffmpeg and libavcodec C libraries for one particular platform, Linux on Raspberry Pi4: https://github.com/Const-me/Vrmac/tree/master/VrmacVideo https://github.com/Const-me/Vrmac/tree/master/VrmacVideo

theLiminator 3y ago
Personally, I use rust for the ability to go as fast as C++ but with far fewer footguns. Not to mention that I personally really enjoy how they made algebraic data types and package management first class. I suspect that if you really spent time learning rust that you'd really appreciate it coming from C++.
- Const-me 3y ago
  When I just want the ability to go as fast as conventional readable C++, I use C# instead. Compared to conventional C++, C# is typically only slightly worse in terms of performance. C# is safer than Rust, and the usability is IMO an order of magnitude better. Just the compilation speed is already a huge contributing factor. I use C++ for 2 main reasons, integration with other software or libraries, and performance. When I need the performance, I don’t write conventional C++. I implement custom data structures, usually use vector intrinsics, sometimes use other platform intrinsics like BMI2, sometimes implement custom threading strategies on top of OpenMP or other platform-supplied thread pools. Most of these things are impossible or very hard to express in idiomatic safe Rust, which means the language constantly gets in the way. Also, most programs contain both performance critical and performance agnostic pieces. When both pieces have non-trivial complexity, I typically use both C# and C++ for the software. Often the frontend part is in .NET, and the performance-critical backend is in C++ DLL.
  - theLiminator 3y ago
    I believe rust is actually more thread safe than C#, though the other points you made are pretty true.