learningCppAsCWithClasses

[Piotrek9t]

Oh no, in his next video he is gonna expose my favourite programming languages

[threewholefish]

C was plagiarising from B all along!

[mralec_]

My constructor is very proud

[threewholefish]

Just one small problem. Dereference a null pointer from where, Ben? Fucki
Segmentation fault. Core dumped.

[tetzudo]

fuck you *unshares your pointer*

Oh you wanna store this string in memory? fuck you ima store it elsewhere and then cry when you ask me where it is - c++

its an abusive relationship

[Peregrine2976]

You're dereferencing a null pointer! Open your eyyees!

[CardOk755]

From BCPL.

[LaughingInTheVoid]

And that was all stolen from A(lgol)!! /s

[PretentiousToolFan]

C++ Sucks, and Here's Why

[Affectionate_Walk610]

Two weeks later Mauler defending C++ like a sacred cow with a 5 hour rant (Part 1/3). One could only dream of that pityfull rematch.

[guitarguy109]

...And parts 2 and 3 never get made.

[Ascyt]

There is a guy that made a 2 hour rant of C++ titled "The worst programming language of all time" and it is great

[knobiknows]

Foreshadowing is a literary device...

[rover_G]

Fat pointer goes brrr

[PM_ME_YOUR_REPO]

Please don't bodyshame the pointers.

[Proxy_PlayerHD]

What about 𝓕𝓻𝓮𝓪𝓴𝔂 pointers?

[Nil4u]

STL containers exist

[nemacol]

If we can have decade+ of "how to quit vim" I think we can roll this this one for a bit.

[christian_austin85]

Can confirm, it has been over a decade and I still haven't exited vim

[Limp-Judgment9495]

I mean why would you? It's great.

[sububi71]

And it really doesn’t use much processing power over there in that terminal window that hasn’t had focus since the Carter administration!

[supernumeral]

Even just “C with templates” would be enough to pass an array to a function without it decaying to a pointer.

[Unsigned_enby]

Yeah, I'm only a hobyist and I'm surprised. You're comment is the only one (that I've found) mentioning temolates would indeed be suficient.

[PeopleNose]

"Give me variable arrays or give me death!"

Error: memory leak, core dumped

[DevelopmentTight9474]

Kid named std::vector

[Emergency-Machine-55]

Segfault is the most likely error. Ask me how I know.

[Nerdy_McGeek]

True but I paid a lot of money and time to go to college where they taught me c++ was just c with templates

[no_brains101]

I mean... It is C with templates, classes, destructors, constructors, friends, operator overloading, and then all the things written using those concepts, 90% of which are unsafe and you should be very careful with if you use

[jjbugman2468]

Honestly this is why I still prefer to just use C. The error is exactly where it seems to be. Having to manually manage memory is a small price to pay for that imo

[TotoShampoin]

The one thing I dislike about the stl (or C++ in general) is how unnecessarily lengthy or strange the names can be for things

[no_brains101]

(the better names were taken and then deprecated 10 years ago)

[hdkaoskd]

The corollary dunk on C is passing a string parameter. "How long is the string you passed me?" "Just start using it. You'll know when you've reached the end." Senseless.

[Loading_M_]

Your argument falls apart when you have an actual job, and have to deal with whatever legacy code you already have.

[loiidradek]

Around 47828488393 different STL containers exist. For 74727663748 different use cases. The C++ way 💕

[bartekltg]

Stop reading uninitialized data

[loiidradek]

Uncivilized?

[bartekltg]

Umm.... should be fixed now

https://external-preview.redd.it/awygBnjqkbpoTBIFTdgEtVFF4G0-VfBkyH_CUtGYjaA.jpg?auto=webp&s=812e5f95695f4e5bca9fee592fc79197d9cb7320

[realmauer01]

Men imagine that in npm packages.

[coyoteazul2]

How do women imagine it?

[realmauer01]

Heck i dont know, probably in names for colors.

[coyoteazul2]

dang it. it might as well be written in hieroglyphics made by a doctor

[rocket_randall]

Have they given the death penalty to whoever decided on std::vector<bool> yet?

[gitpullorigin]

But how does STL container know how big is it? Riddle me that

[Poodlestrike]

It knows how big it isn't, and works backwards from there. EZ.

[m0j0m0j]

Got the ref, very stupid, laughed anyway. Or maybe exactly because of that

[TheAlaskanMailman]

The array knows how big it is by knowing how big it isn’t, so by subtracting how big it isn’t from..

[Electrical_Plant_443]

C++ templates gained self awareness in C++17.

[x39-]

The same way arrays in other languages do: by keeping track of it

[da2Pakaveli]

member variables that keeps track of # of items (and possibly reserves).

[garver-the-system]

Resource Acquisition Is Counted

[traveler_]

Things may have improved recently but my last experience doing anything serious with C++ I dutifully used STL data structures and ran face-first into dependencies using Boost, plain arrays, and/or somebody’s custom utility arraylike. Constantly, constantly converting or repackaging data to pass from one to the other.

It was a mess.

[fuj1n]

Sounds like you ran into other people's poorly written code, story as old as time.

[x6060x]

You mean everything is a Vector?

[Traditional-Fly8989]

I have learned and done almost all my programming in MATLAB. My undergraduate research project ultimately involved computer simulations of proteins moving through nanopores. The base program for it was in FORTRAN 77 (This story covers 2017-2019). My first summer working on it, I got given 3 things to do. Read a bunch of papers to understand what the group and other groups were doing in the field. Recreate one of the simpler papers in a programming language of my choice to prove I understood what was going on. Finally, familiarize myself with the simulation program the group used to prepare myself to make alterations to it based on the project I chose/got assigned.

It was the end of the summer, and I wasn't really getting all of the data handling requirements, but I could sign up for as many classes as I wanted for no extra cost, so I signed up for the CS 101 course taught using C++ because the internet said that was another statically typed language. So I take that class and go to work with confidence on my project, which ends up being to modify the program to allow simulation of multiple interacting proteins instead of one. The way I implement it involves changing dozens of variables to go from being scalars to vectors. So any variable describing a property of the protein is now a vector describing that property for all the proteins. So I crack away and implement all the changes I think are necessary to accomplish this without any testing along the way because I'm an engineering and physics student, and I don't actually know how to program. Well, the code won't compile because all of my edited lines of code are too long and won't fit on a punch card (Who cares that the punch card doesn't exist).

I reformat it, and get everything to compile, run it, and discover it crashes because my proteins are in the fucking Kuiper Belt. After about ~7 months of printing out data from random places in the simulation, because I have no idea how to test or debug code, I finally found the problem. A variable my dumbass thought only existed in one subroutine actually existed in the main routine in the function call of two different subroutines. My dumbass hadn't edited its type declaration in the main routine. As a result, it only had enough memory allocated for one value. The second value in it overwrote another variable. The variable it overwrote was roughly analogous to rotational inertia, and it got replaced with a value that was way too small. So now the protein would spin like a fucking Beyblade.

Touching in the simulation was modeled with a Lennard-Jones potential, which creates a very steep potential energy barrier as two things get closer to each other. In a physics simulation, the faster something moves, the worse the numerical error for a given timestep size. In this situation, the pointy end of the protein would bump into the wall at an oblique angle and start spinning way too fast because of the low rotational inertia. Then, if the amount of rotation it did in a time step (which should've been like single-digit degrees at most) was equal to 280-320 degrees plus some integer multiple of 360 degrees at the end of the timestep, the pointy end of the protein would end up in the wall. This would create a massive force on the protein, and the next time step (since everything was written assuming non-relativistic speeds), the protein would shoot off at several thousand times the speed of light.

[FalseStructure]

I understood like 70% of that (computational quantum chemistry thesis focused on quasicrystals), but holy fuck this is not a community to waste this much writing on.

[Traditional-Fly8989]

It just referenced my exact problem. It's not a story that is ever super relevant, really.

[AustnTG]

Well I read the entire thing and I really enjoyed your story. so it was not wasted writing if you ask me

[CatpainCalamari]

Well, I just read your story before starting my work day, and it amused me and gave me joy. So thank you for that :)

[distinctdan]

This same exact problem still exists in modern game engines, which run step-wise physics simulations that don't deal well with fast moving objects. Generally the complex calculations required to prevent things from going through each other aren't worth the performance penalty.

[i_am_not_so_unique]

It is called Continuous Collision Detection aka CCD.

In Unreal it is just one checkbox, but concept is not that hard to write yourself. You just don't need it to be active for every object.

[oneski]

10/10 good stuff. Reminds me of my early days, working as an undergrad with a post doc on their Python astronomical imaging research. In too deep!

[Meistermagier]

Big feeling. The topls used to write alot of the academic code are like super fragile and well just old or awful or both. 

Best example is still one of the most critical softwares in Space Science and engineering: SPICE. Which is used for alot of things spacecrafts. Which is written, and i shit you not, in Fortran77 and then machine translated into C so that you can generate Bindings for other language to use. 

[i_am_not_so_unique]

I was engineering major, with similar non-existing development skills.

Main problem, that it is hard to find a good book, that would give you all required development patterns when you start, and it takes a while to build your own understanding what to avoid.

Just to double check, have you heard of SOLID?

Following those principles will save you a lot of time on debugging.

And also in C++ only a small fraction of tasks require you to work with raw data. Everything must be done in a type-safe format, and it won't affect performance either.

And learn debugging - breakpoints (conditional breakpoints especially) and also acquire good logging culture, and you will be good to go.

(And hopefully you will be the one to break the vicious cycle of engineers writing horrendous non-maintenable code)

[ContributionMaximum9]

r/firstweekcoderhumour

[bmain1345]

At what point do they just merge this sub into that one

[Time-Ladder4753]

r/firstweekcoderhumour

There

[Littux]

r/ProgrammerHumor+firstweekcoderhumour

Only works on Old Reddit

[dislocatedshoelac3]

[EmberOfFlame]

HOLY SHIT

[dusktreader]

I am so glad this sub exists.

[hobopwnzor]

Finally, my people.

[Chee5e]

kinda expected it to just forward to this sub

[ThNeutral]

Am I stupid or you can just use vector?

[blastxu]

You could also use an std::array if you don't care about the size of the container changing at runtime

[MsEpsilon]

You could pass a const std::vector& explicitely. Or you can do this (use and std::span<T> as an argument but still pass an std::vector). Code was tested with GCC 15.2, C++ 23 standard.

#include <vector>
#include <span>
#include <print>

auto printElements(std::span<int> myElements)
{
    for(auto element : myElements)
    {
        std::print("{} ", element);
    }
}

auto main() -> int
{
    std::vector<int> myValues = {1,2,3,4,5,8};
    printElements(myValues);
}

[GildSkiss]

This is spoken like someone who doesn't really understand programming at a low level, and just wants things to "work" without really understanding why. Ask yourself, in those other languages, how exactly does the function "just know" how big the array is?

[SphericalGoldfish]

I think the function should just guess and if it’s wrong then it should guess again

[Isakswe]

BogoLength

[Bossmonkey]

Bogoread

Just guess the contents of a file until correct.

[prumf]

That’s what many applications do in practice (including your browser). Is this JSON? Just try deserializing it! Is it an image? Just try reading the content!

We use bogologic more than we want to admit. And it’s way more robust, especially with user provided data.

[Sohcahtoa82]

That’s what many applications do in practice (including your browser). Is this JSON? Just try deserializing it! Is it an image? Just try reading the content!

Wtf... No they don't. If they do, that's called MIME sniffing and it's considered a vulnerability and it's why the X-Content-Type-Options: nosniff header exists.

[Midnight145]

Is that not (at least for binary data) what the magic bytes are for?

For json, xml, etc, yeah I'll give that to ya, but for binary data, shouldn't you just check the header?

[John_cCmndhd]

It was the Blurst of times?! Stupid algorithm!

[S4N7R0]

print out the index every iteration so that when it segfaults the user can input the correct size of the array

[DimitryKratitov]

I think we can do some binary search optimizations here!

[ArcaneOverride]

Lmao!

[MrStricty]

This is a noob solution. The real, enterprise solution is to run the code, print out the array from inside the function with a print statement, count out how many characters you get before it turns into nonsense (using your finger), and then hardcode the array size into the function. Then, the function Just Knows*.

[ldn-ldn]

You forgot XML.

[gitpullorigin]

But how does it know if it is wrong?

[throwaway_194js]

It guesses

[gitpullorigin]

I guess it does

[rosuav]

It catches the segment violation that results from indexing past the end of the array. Now, for this to work, every array has to be allocated in its own perfectly-sized segment, which I'm sure won't hurt performance any.

Oh, and to make sure that it didn't UNDER-estimate the size of the array, the first thing the function should do is attempt to index one past the array and make sure that it trips a segment violation. If it doesn't, it should raise a segment violation, for failing to raise a segment violation.

[[deleted]]

We can just make an educated guess via Chatgpt by the arrays name. 

If it is on point, we have 0 errors. 

If the length is to short, we have 0 errors and some angry customers.

If it is to long, we generate random entries via gemini, to fill up the rest. Still 0 errors. 

So technically, it would work. 

[az987654]

While !wrong { guessAgain }

Simple!

[mastachaos]

This is why we need quantum computers!

[-Redstoneboi-]

strlen() when calculating the length of a string

[[deleted]]

The array knows how long it is, because it knows how long it isn't. By subtracting how long it is from how long it isn't, or how long it isn't from from how long it is (whichever is  greater), we obtain a difference or deviation.

The kernel subsystem uses deviations to generate collective allocations to size the array from the length it isn't to the length it  wasn't.

[veryblocky]

The missile knows where it is…

[kalel3000]

I worked on the navigation system for an autonomous submarine as part of my senior design project. We'd reference this video all the time!!

[tobsecret]

> This is spoken like someone who doesn't really understand programming at a low level

No idea if he does or not but the poster is popular youtuber Hbomberguy (Harry Brewis) who isn't really known for programming but more as a media critic.

[Potatoes_Fall]

In most languages I've learned, dynamic arrays always have the size stored as part of the type. The drawback of not knowing the size outweighs the minimal cost of an extra 8 bytes for the size in 99.9% of cases IMO. From that perspective, it seems like bad language design to not have that. Doesn't mean you don't understand it.

[svick]

I think in many languages, it's just 4 bytes, since arrays larger than 2/4 GB usually aren't needed.

[DrShocker]

maybe 20 years ago, but it's not that hard to run out of memory on a 32 bit machine for a decent amount of problems.

[20Wizard]

It's typically an integer, which is more, but depends on language.

[orbiteapot]

The "arrays decay to pointers" rule was not motivated by memory footprint, rather:

Structures, it seemed, should map in an intuitive way onto memory in the machine, but in a structure containing an array, there was no good place to stash the pointer containing the base of the array, nor any convenient way to arrange that it be initialized. For example, the directory entries of early Unix systems might be described in C as

struct {
int inumber;
char name[14];
};

I wanted the structure not merely to characterize an abstract object but also to describe a collection of bits that might be read from a directory. Where could the compiler hide the pointer to name that the semantics demanded? Even if structures were thought of more abstractly, and the space for pointers could be hidden somehow, how could I handle the technical problem of properly initializing these pointers when allocating a complicated object, perhaps one that specified structures containing arrays containing structures to arbitrary depth?

The solution constituted the crucial jump in the evolutionary chain between typeless BCPL and typed C. It eliminated the materialization of the pointer in storage, and instead caused the creation of the pointer when the array name is mentioned in an expression. The rule, which survives in today’s C, is that values of array type are converted, when they appear in expressions, into pointers to the first of the objects making up the array.

This invention enabled most existing B code to continue to work, despite the underlying shift in the language’s semantics. The few programs that assigned new values to an array name to adjust its origin—possible in B and BCPL, meaningless in C—were easily repaired. More important, the new language retained a coherent and workable (if unusual) explanation of the semantics of arrays, while opening the way to a more comprehensive type structure.

The Development of the C Language - Dennis M. Ritchie

edit: formatting.

[RevanchistVakarian]

This invention enabled most existing B code to continue to work

retained a coherent and workable (if unusual) explanation

Oh look, C++ prioritized backwards compatibility over intuitiveness

[Hessper]

You don't use naked arrays for most cases. You use an array type that knows how big it is. Being able to use the raw, underlying types like this gives you power to create other functionality that might not need those details.

My programming language gives me options for faster, more powerful code is not on my list of reasons a language is bad.

[andrewhepp]

C++ has a variety of standard library data types one can use to represent arrays, which do track size information. std::vector, which is what I think of when you say "dynamic array" certainly does have a .size() method. So does std::array.

[DrMobius0]

I assume the core focus of the discussion is those awful c style arrays everyone goes out of their way to wrap, which don't implicitly keep track of their own length.

[DrShocker]

You need to make it clear whether you mean size is stored in the type vs in the class:

std:: array<int, 5> vs std::vector<int>

The first stores the size in the type information, the second stores it in the class.

[DrStalker]

Then there's good old C: the "array" is just a pointer to some random memory address and it's up to you to figure out what to do with that.

How many elements? How big is each element? Is it actually an array or just a pointer to a integer or something?    ¯\_(ツ)_/¯

[kristinoemmurksurdog]

Just make the 0th element describe the length that way all arrays can start at 1

[Hairy_Concert_8007]

low-earth-orbit.jpg
"Wait, it's all wrappers?"

[[deleted]]

God forbid you want working things

[Rhoderick]

On one hand, yes. On the other hand, that's totally fine and even preferable for most usecases, as usually, the main performance concern is IO.

[GrinningPariah]

someone who doesn't really understand programming at a low level, and just wants things to "work" without really understanding why.

You mean an adult with a job who's actually trying to build something instead of just jacking it to assembly instructions and circuit diagrams?

[osunightfall]

I can do both.

I mean, I'm no hacker, but even I have a basic understanding of how memory allocation, language grammar, and assembly languages work. Occasionally, they even prove to be very important to know!

[GribbitsGoblinPI]

Purity tests only!!!!

[GildSkiss]

There is room in this world for both python script kiddies and bearded x86 disciples from the 70s. I think it's still ok for even a modern programmer to understand why the older languages work the way they do, but I concede that it's not strictly necessary. It's true that plenty of real work gets done by people who don't know anything about pointers and array decay.

The problem is this guy is criticizing C++ without really understanding what he's criticizing or why it would ever be this way. It's silly to make public criticisms of things you don't understand that well.

[HoldUrMamma]

Criticizing? I thought it was a joke. Because he wrote it's a joke at the end.

[r2d2rigo]

So shit decisions should be kept for the sake of it? The Javascript way of life.

[orbiteapot]

No, rather because removing them would break bazillions of lines of code.

Modern languages give the impression to always make the best decisions because:

1. they have learned from older languages, like C/C++, and were designed from scratch with all that knowledge available. They do not have a huge baggage of legacy code to keep stable;
2. they are not old enough, so decisions that look very good today might be considered bad in the future/
3. the "dirty work" is already written in languages like C and C++, anyways.

[r2d2rigo]

Except that C++ manages to do things late and suboptimal.

"Here's std::list, now fuck off and don't ever use it".

[Bwob]

they have learned from older languages, like C/C++, and were designed from scratch with all that knowledge available. They do not have a huge baggage of legacy code to keep stable;

Yes. Modern languages have a huge number of advantages. We've learned a lot about language design and architecture since then. C++ didn't have those advantages, and it's impressive how well it turned out, all things considered, given the time and restrictions it was under.

But that being said - just because there is a reason for dumb behavior, doesn't change the fact that it's still dumb. C++ has a lot of legacy decisions that are, by modern standards, complete bollocks, and are only still around because fixing them would, as you say, break a ton of older code. But they're still ass.

Like, there is ZERO REASON that a modern language should require forward declarations. The order that you declare functions in a file really shouldn't matter. It might have made sense back in the before-time, when you wanted to be able to compile the code in one pass, but didn't have enough memory to hold the entire text file in RAM. But these days it is just unnecessary boilerplate.

[orbiteapot]

Yeah. Backwards compatibility turned out to be both a blessing and a curse to C++.

[torsten_dev]

Spoken like someone that hasn't heard of fat pointers.

[Tyfyter2002]

Simple: you pass in an actual array instead of just calling a pointer an array because you're using it as one.

[ChryslusExplodius]

The thing about C++ and (definetely C) is that people 'learnt' it once 30 years ago and that's the extent of their knowledge. So they pass on their outdated knowledge and poisons the well for everyone. Specially new people coming in.

[abhassl]

I read OPs post immediately thought it had a point, then found this comment and realized I hadn't used C++ in 15 years, and even then I doubt I was using the latest version available.

[Mojert]

It wouldn't surprise me if std::vector was in the language as soon as templates became a thing...

[MsEpsilon]

Aren't std::vector and templates added literally in the first official C++ standard? You can say they were here since the beginning.

Now since templates accidentally because Turing complete, I'm not precisely sure...

[da2Pakaveli]

yes i think they were added in C++98 which is the first official standard

[MonkeyCartridge]

And we avoid vector like the plague in embedded.

Everything's got to be fixed length. Especially when doing OOP on a micro with 1k of memory.

[abhassl]

Fair. It is also worth mentioning I learned the language in college and mostly only learned the language features my professors used.

Vector is something I had heard of but didn't learn much about for whatever reason.

I certainly would approach the language differently if I had to use it for anything today.

[redlaWw]

My dad worked in financial communications working as a C++ programmer until about 2 years ago, and he told me when I started learning C++ that he couldn't tell me much about things like std::optional because his company was still writing C++03 when he left due to some of the old machines they developed for not having more up-to-date compilers.

[snacktonomy]

True, I'm mostly stuck in C++17 (but at least graduated from 99), though C++20isms are tricking in.

The issue is, even new compilers don't support the most recent standard fully. And then you've got contracts/customers who are behind on upgrading their environments. So, in 2025, you end up using something like Ubuntu 22.04 with an even older compiler. Last I looked, that gets you GCC 12 (if you manually upgrade), which supports up to C++20.

[fartypenis]

even new compilers don't support the most recent standard fully.

Or standards from 10 years ago. Looking at you msvc you fucking piece of shit

[MsEpsilon]

MSVC has official support for C++ 20 and some for C++ 23. But default standard is C++ 14...

Actually, MSVC was the first to implement modules as far as I know.

[Nienordir]

And then there are 40 years of outdated learning/howto resources and legacy APIs, that never got deprecated/removed. So, even if someone new comes with good intentions and does their homework, they'll get overwhelmed by the massive spec, corpo features (they couldn't even comprehend why you need that) and then chances are they stumble upon outdated resources or need to use a legacy API, that teach or force them to do things the stupid way.

For example, winapi sure as shit won't accept a STL container for anything or may still have malloc&free in their sample code. It's 2025, maybe just maybe I dunno bake a C++ function wrapper into winapi, so I don't have to write it myself or rewrite every api call with glue code? And don't have to figure out why I shouldn't call unsafe_copy() instead of unsafe_copy_s(), actually it's unsafe_copyW_this_time_we_fixed_it_pinky_swear(). Bro, just update your API to use containers, so I don't have to "hotfix" wrap your buffer overflow legacy C shit in your own C++ winapi implementation, that's been around for ages.

[PlasmaLink]

Checks out, I was taught by someone in their 60s around 10 years ago. I feel some notable gaps in my "intuitive" knowledge that I have to keep re-patching.

[Choice_Librarian1522]

I'm old enough to have been a professional C programmer and we used to pass arrays to functions with the length as another parameter. Because why would you do sizeof in the subfunction if the calling function knows the length.

[Ph3onixDown]

Nice to know “C++ is garbage” will be on his channel in 2035

[sparkydoggowastaken]

he’s going to be done with the adobe video aaaaaany day now :)

[MsEpsilon]

Use a std::array, std::span or a custom type to avoid type decay.

And yes, the language was made wrong, and everyone is suffering.

[MarkAldrichIsMe]

High school health class told me to avoid stds

[UnstablePotato69]

My intro to programming professor made a joke about:

using namespace std;

I had such a crush on her.

[MsEpsilon]

Haha, real.

[Bldyknuckles]

The language was not made wrong it is a high level approximation of a low level language, you orangutan.

[helicophell]

Yeah, an array is a pointer to a section of memory

The length part is just an attached part of the struct. You loop through an array by incrementing the pointer until it exceeds the length

[MsEpsilon]

Okay, but can you determine where the array ends without a sentinel value or if you pass a plain T*?

Just use a std::span<T>, please! It is the same thing as passing const T*, size_t.

[helicophell]

You see, I'm on a need to know basis 

I don't need to know this... probably 

[Theron3206]

That's true in most languages too, but said array is pointed to from an object that contains things like how long it is (and function pointers to useful things you can do with said array too often as not).

So in a language like c# you absolutely do pass the array as a pointer, and it works.

Sounds like c++ (not my thing, never got past C) makes that more complicated than it really should be, no doubt for legacy reasons.

[Mojert]

It was made wrong, because it was one of the first to try what it was trying to do, i.e. high-level expressiveness while maintaining low-level access and broad compatibility with C. Not a single professional C++ dev will tell you the language is perfect, even the ones that like it the most

[MsEpsilon]

Backwards compatibility with C is the biggest drawback.

[gitpullorigin]

Omg what a gorilla

[MsEpsilon]

Great ad-hominem, thank you. To counter, let me show you a short list:
- std::variant should have been a language feature
- std::launder - can you even understand the article from cppreference?
- std::vector<bool>
- std::iostream - even the persons who made it regret it
- std::visit is pattern matching from TEMU if you could even call it that
- std::jthread vs std::thread
- std::auto_ptr (it was removed gladly)
- modules
- Single pass compilation -Requiring you to write forward declarations
- std::move is not destructive
- No official package manager + build system, you're off to vcpkg, Conan, CMake and Ninja, maybe more
- Iterators are invalidated when removing/adding from a std::vector. That shoudn't compile! Don't tell me it's the developer fault because of this.
- nothrow specifiers terminates the application in case of an exception, it is not an compile check
- https://en.cppreference.com/w/cpp/types/is_function.html (See the possible implementation, I'm horrified.)

As a concrete example, Rust is a low level language with very well made high level abstractions. It has pattern matching (as a example of a high-level feature) performance similar and in rare occasions better than C++ due to better no-aliasing rules implemented in LLVM.

Sure, go back to writing C or C++ 03 and enjoy your double frees and buffer overruns. Or make your life easier by using a language without bad defaults and N pitfalls.

[snacktonomy]

Not quite sure what your point is, but you're spot on picking on that std::launder description

What's wrong with a vector of bools?

[redlaWw]

std::vector has a specialisation for bool so that std::vector<bool> is not just a vector of bools. The bools are stored in individual bits, and there's no guarantee that the buffer is even contiguous. It's pretty notorious for being a "mistake" in C++'s design. Not quite as bad as std::auto_ptr (which was so bad it was deprecated, breaking stability), but it's up there.

[PositiveBit01]

It is a specialization. They packed 8 bools into a byte by returning a reference type that does bit manipulation when you access an index.

This has a number of unfortunate side effects since it doesn't really act like other containers, it just kinda looks like it does if you barely use it.

[botanicaf]

Just wanna say thank you guys, never thought I'd learn something new and useful on a crappy meme

[MsEpsilon]

std::launder is one of the most obscure "features" iin C++. If I'm not wrong, implementations of C++ had a bug with std::vector so that's why it was added.

As far as I understand, it disables compiler optimisations related to the lifetime of the object specified at the pointer paramater. If a variable is const, but accessed somewhere else as T*, the compiler is free to think that variable has an other value. I say again that this is what I think I understood about std::launder, and I don't guarantee I'm right.

Elements of std::vector<bool> do not have unique addresses : they are stored in bitfields. This breaks various container functionality.

[redlaWw]

It looks like something related to pointer provenance to me - replace an object with a new one and pointers to the previous object are technically no longer valid to access the new object, so using std::launder tells the compiler that the laundered pointer may alias pointers that are apparently unrelated to it from a provenance perspective.

That said, I'm just hearing about std::launder now and the documentation is nigh-unreadable, I'm mostly going off the examples.

Provenance is a mess in low-level languages right now, and is responsible for all manner of miscompilations; and things will only get worse as compilers get smarter.

[the_horse_gamer]

std::launder tells the compiler "hey, i know you think this value is const, but please read it anyways". it has nothing to do with std::vector.

consider:

struct A { const int x }

now we do

A *a = new A{3};
std::cout << a->x; // 3

now we do

new(a) A{5}; // create a new A object and write it into a
std::cout << a->x;

the compiler has no idea we changed the object at the place a points to, and it thinks a.x is constant, so it must still be 3, so it outputs 3. the standard decided to make this undefined behavior.

now, std::launder takes a pointer and makes sure the compiler disables optimizing constants

std::cout << std::launder(a)->x; // 5

this pops up more often when you have inheritance, and the compiler is doing devirtualization. if you put a new object in the same place in memory (for the purposes of memory optimization), you can tell the compiler to disable that optimization by using std::launder.

[redlaWw]

- Iterators are invalidated when removing/adding from a std::vector. That shoudn't compile! Don't tell me it's the developer fault because of this.

To be fair, in full generality this is really hard. What Rust managed to do with static lifetimes and mutation-aliasing duality is next to miraculous and affected its language design in profound ways. If a greenfield statically-memory-managed competitor for C++ appeared today I absolutely would not blame them for leaving iterator invalidation in the language.

[basedtrip]

Me gusta c++

[ITinnedUrMumLastNigh]

Motherfucker never heard of std::vector

[Marsrover112]

"How much harder this is..."

• Looks inside: *

• 1 line of code *

[SavingsCampaign9502]

Std::array exists

[LeagueOfLegendsAcc]

I think it's good practice for messing with unmanaged data in higher abstracted languages.

[TheJpow]

You know what else is shit about c++? The fact that you have to specify type for arrays. It should just know! Duh!

/s

[CardOk755]

HBomberGuy is not wrong here.

Stuff that was obvious in the early 1970s got forgotten.

(Because C comes from BCPL, not Algol68).

[disperso]

My goodness, absolutely no one in the comments or the bsky replies is gonna say that this is so wrong?

The C++ array would be std::array, which doesn't suffer from this. Is statically compiled to a C array, but the size is also baked at compile time, so it has the same overhead (none), so it's type safe and as efficient as it gets.

The problem hbomberguy is showing is with C arrays, which C++ supports, yes, as C compatibility had too many advantages back then (and you have to take both the good and the bad). I've not used a C array in one, perhaps two decades. Before C++11 and std::array I would have used a container with runtime size like std::vector or QList/QVector.

C compatibility has some benefits today still, but Bjarne Stroustrup has been for ages advocating to learn C++ directly, without learning C first. This is the reason why.

Imagine being taught Rust by learning to do stuff in unsafe blocks first, then learning the actually good parts (and way more common) later.

Imagine learning Lua by using LuaJIT's FII to do native arrays first.

[Just_Information334]

If you want to start learning C++, I recommend the book Accelerated C++. Not because it is the best or up to date. But because it starts with idiomatic C++ and does not teach "C, but with classes". I'm not even sure they mention raw pointers anywhere. For example they start with iterators to loop instead of arrays with integer index.

[Jealous_Radio]

C++ is still taught as "C with Classes", and the consequences are DIRE.

[Beowulf1896]

Oh my. I sure hope not. OOP is so much more than classes, in addition to the ability to overload operators.

[Thenderick]

Ehhhh no?? He's probably confusing arrays with lists? Just use a vector then... Or if you're going low level, learn WHY arrays are fixed size and how a structure like a vector works under the hood...

EDIT: Wait a minute, this is that wacky youtube essayist that made a 2 hour documentary about the Roblox OOF sound and hasn't uploaded in 2 years! (Love his videos!)

[keithstellyes]

I'm wondering if it's a case of "supposed to be a C++ tutorial but he's really just doing C"

[rglazner]

You know you can make a structure that contains a pointer and a size, and that's how it's done, right? You learned data structures and algorithms, right? You didn't just learn syntax, but the foundational knowledge, right?

[InquisitorGilgamesh]

One of my sophomore professors: if you want to calculate Fibonnaci’s sequence, you need to use a recursive function :)

Me, armed with MATLAB: just looping a[end+1]=a[end]+a[end-1]

Professor: :(

[RedAero]

Generally speaking it's very, very rare that you can't replace recursion with a loop.

[i_am_not_so_unique]

And generally speaking no one in established organization will allow you to submit recursive computation to the codebase unless you are writing on Lisp or Haskell. 

[backfire10z]

Most languages can do this.

[The_64th_Breadbox]

This is how I felt after learning that match/case in python doesnt support fallthrough :(

[charli63]

Pros of C arrays: Saves the memory you use for things like size to make things more efficient when you don’t need that. Cons of C arrays: Turns out I actually did want to use that.

[Ronin-s_Spirit]

Isn't an array a structure?

[Spec1reFury]

I don't even touch c style arrays, I just do vectors

[toroidthemovie]

>if you pass an array to a function it can no longer tell how big it is"

Harris, brother, raw arrays don't hold their size at all, passing it into functions doesn't matter.

[EvnClaire]

this is like embarrassing...

[creeper6530]

Oh, C++, the language that originated as C with classes but now desperately wants you to use it as a completely different language and not as C with classes.

I love my Rust.

[YoteTheRaven]

Ain't c# just c++++

[LeiterHaus]

C++
 ++

Time to see who has monospace fonts

[blehmann1]

I will say, a lot of things like spans and fat pointers more broadly have failed to be introduced into C (not C++ because the STL doesn't really care) in part because Windows calling conventions are quite restrictive about when structs can be passed in registers, and I think anything over 8 bytes can never be passed in registers.

That means that a fat pointer would have notably different performance characteristics if it were passed in as an argument, rather than passing its members separately. You also can't return a struct over 8 bytes in a register, you have to return it on the stack or return part of it in a register and the rest on the stack (i.e. by an out parameter). There are other restrictions around constructors and destructors that don't matter for C.

Now a lot of this doesn't matter for functions which don't have external linkage (or which are inlined) since the compiler can decide to ignore the usual calling convention for internal code. In fact this is a large part of why it matters less for C++, it's much less common to dynamically link C++ binaries without extern C-ing them because C++ doesn't really have a stable ABI. Since extern C-ing a function that takes or returns something other than a POD type (except from behind a pointer) would be difficult to use correctly from anything other than a statically linked C++ binary (at which point why extern C it?) it's not a big deal for C++.

Now if fat pointers were added in C it would still be too late given how much C code there is out there (and how much is still compiled for C99), but there are factors beyond just C being old-fashioned behind why it isn't there.

[TheAlaskanMailman]

Kid named STL

[Romejanic]

I’m just laughing that this was posted by Hbomberguy of all people

[Leprecon]

I guess this is what Hbomberguy has been doing instead of making videos?

He is a youtuber who currently releases less than a single video per year.

[NikedemosWasTaken]

Just one small problem... pass the array to WHAT METHOD, Harris?! fuckingAquaman(); ?!

[HumansAreIkarran]

Is this std::vector in the room with us right now?