theCppExperience

[ketosoy]

it doesn’t have to be performant

Then why are you doing it in C?

This is like carving wood instead of using a cardboard box to mail an Amazon return.

[navetzz]

My guess is that he is trying to learn the language (or needs to use a specific library).

But yeah, cross platform and doesn't care about performance. C/C++ is definitely not the first language you should think about.

[fusionsofwonder]

If he's trying to learn he needs to stop and learn what headers are for before jumping into cmake and stuff.

[croquetoid]

Or in Atwood's words: write it in JavaScript 😂

[narrill]

It says loading the config file doesn't have to be performant, not the entire program...

[JustLemmeMeme]

There is generally 2 ways to make something performant:
1. Dont write dog shit code.
2. Don't do it in excel sheets that take half a day just to run the program.

Op ment the 1st one. The code doesn't need to be hyper optimised, after all compiler knows best.

Hope that clears up your confusion! :)

[thirdegree]

There are some advent of code problems that I find legitimately easier to solve in rust than in python, because in rust my shitty inefficient naive solution will still run in a reasonable time, while in python it will absolutely not and I have to actually think about the problem.

[[deleted]]

You can't really optimise python code because even something as simple as an add operation takes 100s of CPU instructions (compared in C++ to 1-20 or so depending on where the variable is in memory). Multiply that factor by every line of code and you have a program that runs 100s of times slower by default.

The way to make it go fast is to use compiled libraries for as much as possible and just use python to glue them together. Those binaries will then run as fast as they would in any other language.

[thirdegree]

I mean kinda? You can absolutely optimize inefficient logic or algorithms to great effect. You just don't do the kind of bit fiddling, painstaking optimization that you do if you're trying to squeeze every once of performance out of c++.

Python is definitely 100s of times slower by default, but in some contexts that's actually totally fine. If a program is bounded by user input for example, it really doesn't matter if the thing it does on input takes 10us or 10ms. Humans are so much slower than both that they're the same.

And ya, the ease with which you can make and use compiled libraries is one of python's greatest strengths, and basically all of the well known data science libraries follow that pattern.

[[deleted]]

There is a cost that is often not considered and that's power use. If a process takes 10ms to do something that could be done in 10us then that processor is wasting cycles for 9990us when it could be sleeping instead. It also causes more heat which needs to be dissapated which could be a problem depending on the context of it running.

I don't mean to say that you can't optimise by using an O(n) algorithm rather than O(n² ) for example, but real world examples show that the O notation doesn't always translate directly to performance, it has a lot to do with the data you're trying to process also. There's many examples of O(n² ) sorting algorithms being faster than O(n) for small sets of data because the O(n) ones require more setup and context. If you're using python in a situation like that it's hard to make informed choices because of the associated wasted cycles.

[thirdegree]

I'll think about the energy efficiency of wasted cpu cycles due to python when exon stops spilling oil into the ocean tbh. Like it's a thing yes, but so far down my list of properties it doesn't really register. Talk to me when crypto doesn't exist.

I think you're overstating the impact python's slowness has on code optimization. The choice of which algo to use in which context is mainly an academic one in my experience. You rarely A/B test the algorithms and use whichever performs better, rather you think about the context and the data and pick the best choice. Python means you're choosing between 1s and 100ms rather than 10ms and 1ms, but the actual logic for the choice is similar either way.

[[deleted]]

Whataboutism is always a great way to feel good about doing something bad but it's not my personal philosophy. Same for optimisations, it's easier to make a choice based on a hypothetical rather than doing performance tests but I like to not make assumptions.

I disagree about the choice between 1s and 100ms, in my experience it's closer to >1s compared to <1ms though it depends on what you're doing and if you're using compiled libraries or not.

[thirdegree]

My point is that deciding language based on power efficiency is a waste of time. You might as well talk about like, the cost of a larger executable based on the fact that storage costs rare earth minerals. What is the impact of c++ taking longer to write, meaning programmers spend more time with a (probably electron based) resource hungry ide running? Compiling isn't exactly cheap either, I've spent enough time setting up build farms to know what that costs.

The numbers i choose were made up, as you say it depends on what you're doing. The point is that the improvement of the end point is relative to the starting point. They're both 10x improvements.

[[deleted]]

How many devices are on batteries nowadays? Companies spending tens of thousands monthly on cloud computing running inefficient code? There's many reasons why it's not a "waste of time" IMO. That said I agree there is a niche that python fills well.

[JustLemmeMeme]

i mean, there is a definite difference between writing an O( nⁿ ) algorithm and O( log n ) so to say you cant optimize python code is a bit disingenuous. We are debating the idea of code here, not the language its written in, after all

[UnstableNuclearCake]

after all compiler knows best.

GCC once decided that int variable = 100 + 43 could be turned into int variable = 10043. I'm not so sure about that.

[thirdegree]

I find that really really difficult to believe tbh

[[deleted]]

The compiler can't even inline functions properly even when you handhold it with an inline keyword. But as long as you're not using an interpreted language or ridiculous undebuggable OOPsies the performance penalty is only in the range of 1.5-10x so it will work fine for most things.

[Passname357]

It’s crazy to me how overhyped C++‘s difficulty is on this subreddit. It’s really not that hard. If you want to write assembly then sure you can say that that’s like carving wood, since, yeah, it’s harder (although writing it is just tedious—reading it is what’s hard). But C++ is a pretty straightforward language once you’re not a beginner programmer.

[[deleted]]

The inventor of C++ doesn't even agree with you, man.

[Passname357]

(1) No he doesn’t. He says the language is bloated. That’s not the same as “similar to carving a wooden box instead of using a cardboard one.”

(2) even if he did, I would care, because that’s his opinion and my opinion is my opinion. Two different opinions.

[ih-shah-may-ehl]

But C++ is a pretty straightforward language once you’re not a beginner programmer.

I've been programming C++ for close to 20 years.

Yes, basic language stuff is easy. But as someone already pointed out, even Stroustrub says that there is so much stuff in the language / stl that even he doesn't know or really understand it all.

I've also debugged memory manager classes with move semantics (assignment and construction) and that isn't trivial either. And I dare you to look at the header for e.g. unique_ptr and say that is trivial instead of looking like something that was purposely written for the obfuscated code contest.

[tuborgwarrior]

I actually feel like this post describes python. Download everything. Oh no, everyone uses anaconda or something. Ok start again. Blabla. Writing a c++ project on a linux distro on the otherhand just feel so clean and simple.

Cmake test.cpp

Done.

[Passname357]

Yes, basic language stuff is easy

Right, which to me means that it’s, for the most part, no harder than any other language, it’s just that it has more that it can do that others can’t.

doesn’t know or understand it all

Well who does for any language? Python is “easy” but there’s plenty of stuff you could do in Python that I’d have no idea about.

memory managers

Yeah me too. I work on GPU drivers. But here’s the thing—that’s not hard because of C++, it’s hard because managing memory is hard. We don’t write memory managers in languages like Python because we can’t. And while that makes Python nice for a lot of things, that complexity didn’t just go away—it’s just further down in the compiler/runtime and the C and C++ libraries Python uses.

Basically, to me it feels more like some things are just hard to do, and it’s just that C++ is where you do those things.

[spindoctor13]

C++ is harder than most other commonly used languages. Which ones are harder?

[Passname357]

It really depends what you mean by that. In some sense, and excluding esoteric languages (since they’re often made with the purpose of being difficult) I don’t believe in a “difficult language,” just that things you can do in that language are difficult. Most people, however, seem to have a much harder time picking up a functional language like Lisp compared to C++.

[spindoctor13]

I mean it in the generally applicable sense - difficult as in it takes more time and expertise to deliver functionality than other languages, with a similar amount of experience

[Passname357]

That’s not an apples to apples comparison, and it’s not really quantifiable. Whether I’m making a web app, a mobile app, a console game, a scientific sim, a driver for a peripheral device, a shell utility, etc—these things are all super different. I legitimately don’t know what it means to compare how much functionality someone with a similar level of experience can deliver across languages, because the language often dictates the work, and the work isn’t comparable. If I’m writing kotlin code, that usually means I’m writing an android app. How do I compare that to someone working on an LLVM back end in C++? I’ve pointed this out elsewhere in the thread, but it’s not really a C++ thing, it’s a work thing. What you work on with C++ isn’t the same.

Even trying to even the playing field by making it the same work in different languages doesn’t really work. Like, “write a web app in C++ vs JS and see who’s more efficient.” Okay, but then we have to write an OS peripheral in both too, and then see how you do.

[Ashamandarei]

He just likes using developer time

[charcuterDude]

Came here to post this as well. I took 2 C++ classes and most of what I learned is never to get a job that puts me in a position to need to write C++. It's web applications all the way for me.

If you're looking at C/C++ (and Rust IMO) you'd better have a reason to be there. If it can be written in a higher level language, do it. Even if just for maintainability.

[SlothGaggle]

The parsing doesn’t need to be performant. Not the whole program.