I don’t think that casting a range of bits as some other arbitrary type “is a bug nobody sees coming”.
C++ compilers also warn you that this is likely an issue and will fail to compile if configured to do so. But it will let you do it if you really want to.
That’s why I love C++
What do you mean I’m not supposed to add 0x5f3759df to a float casted as a long, bitshifted right by 1?
//what the fuck?
C++: all the footguns you need plus a lot more that you never imagined in a single language
There are no medals waiting for you by writing overly clever code. Trust me, I’ve tried. There’s no pride. Only pain.
Not only that, but everyone who sees that code later is going to waste so much time trying to understand it. That includes future you.
Debugging code is always harder that writing it in the first place. If you make it as clever as you can, you won’t be clever enough to debug it.
Some junior will call it ”skill issues” and then write the most unreadable code ever.
“C++ compilers also warn you…”
Ok, quick question here for people who work in C++ with other people (not personal projects). How many warnings does the code produce when it’s compiled?
I’ve written a little bit of C++ decades ago, and since then I’ve worked alongside devs who worked on C++ projects. I’ve never seen a codebase that didn’t produce hundreds if not thousands of lines of warnings when compiling.
You shouldn’t have any warnings. They can be totally benign, but when you get used to seeing warnings, you will not see the one that does matter.
I know, that’s why it bothered me that it seemed to be “policy” to just ignore them.
I put -Werror at the end of my makefile cflags so it actually treats warnings as errors now.
0 in our case, but we are pretty strict. Same at the first place I worked too. Big tech companies.
Ideally? Zero. I’m sure some teams require “warnings as errors” as a compiler setting for all work to pass muster.
In reality, there’s going to be odd corner-cases where some non-type-safe stuff is needed, which will make your compiler unhappy. I’ve seen this a bunch in 3rd party library headers, sadly. So it ultimately doesn’t matter how good my code is.
There’s also a shedload of legacy things going on a lot of the time, like having to just let all warnings through because of the handful of places that will never be warning free. IMO its a way better practice to turn a warning off for a specific line.. Sad thing is, it’s newer than C++ itself and is implementation dependent, so it probably doesn’t get used as much.
I’ve seen this a bunch in 3rd party library headers, sadly. So it ultimately doesn’t matter how good my code is.
Yeah, I’ve seen that too. The problem is that once the library starts spitting out warnings it’s hard to spot your own warnings.
Yuuup. Makes me wonder if there’s a viable “diaper pattern” for this kind of thing. I’m sure someone has solved that, just not with the usual old-school packaging tools (e.g. automake).
A production code should never have any warning left. This is a simple rule that will save a lot of headaches.
Ignoring warnings is really not a good way to deal with it. If a compiler is bitching about something there is a reason to.
A lot of times the devs are too overworked or a little underloaded in the supply of fucks to give, so they ignore them.
In some really high quality codebases, they turn on “treat warnings as errors” to ensure better code.
I know that should be the philosophy, but is it? In my experience it seems to be normal to ignore warnings.
My team uses the -Werror flag, so our code won’t compile if there are any warnings at all.
C++ is kinky that way. You can consent to all manner of depraved programming patterns. Great for use in personal life, but maybe not appropriate for the office.
But does it have cargo-mommy :P
https://github.com/Shadlock0133/cargo-vibe
I thought it was a joke, but this is actually viable and even configurable
By default,
cargo-vibewill, on success, vibe full strength for 3 seconds.You can change that by setting
CARGO_VIBE_PATTERNenvironment variable. For example, to set it vibe for 1.5 second on 20% strength, you can do:CARGO_VIBE_PATTERN="0.2 1.5s" cargo vibe <cmd>You can also set full patterns of vibes to run, by separating them with slashes
/. Here is one example:CARGO_VIBE_PATTERN="0.4 1s/0.6 1s/0.8 0.75s/1.0 0.25s"Wait, there’s more! https://github.com/funkeleinhorn/cargo-shock
To let Cargo Shock trigger your shock collar use:
cargo shock buildTo use it everytime you can
alias cargo="cargo shock".Cargo Shock can also be combined with other tools like Cargo Mommy and Cargo Vibe like this:
cargo mommy vibe shock build ...And they have a really slick site: https://openshock.org/
TIL there’s more than one kind of “vibe” coding.
But it will let you do it if you really want to.
Now, I’ve seen this a couple of times in this post. The idea that the compiler will let you do anything is so bizarre to me. It’s not a matter of being allowed by the software to do anything. The software will do what you goddamn tell it to do, or it gets replaced.
WE’RE the humans, we’re not asking some silicon diodes for permission. What the actual fuck?!? We created the fucking thing to do our bidding, and now we’re all oh pwueez mr computer sir, may I have another ADC EAX, R13? FUCK THAT! Either the computer performs like the tool it is, or it goes the way of broken hammers and lawnmowers!
Ok gramps now take your meds and off you go to the retirement home
Stupid cloud, who’s laughing now?
I will botton for my rust compiler, I’m not going to argue with it.
when life gives you restrictive compilers, don’t request permission from them! make life take the compilers back! Get mad! I don’t want your damn restrictive compilers, what the hell am I supposed to do with these? Demand to see life’s manager! Make life rue the day it thought it could give BigDanishGuy restrictive compilers! Do you know who I am? I’m the man who’s gonna burn your house down! With the compilers! I’m gonna get my engineers to invent a combustible compiler that burns your house down!
Soldiers are supposed to question potentially-illegal orders and refuse to execute them if their commanding officer can’t give a good reason why they’re justified. Being in charge doesn’t mean you’re infallible, and there are plenty of mistakes programmers make that the compiler can detect.
I get the analogy, but I don’t think that it’s valid. Soldiers are, much to the chagrin of their commanders, sentient beings, and should question potentially illegal orders.
Where the analogy doesn’t hold is, besides my computer not being sentient, what I’m prevented from doing isn’t against the law of man.
I’m not claiming to be infallible. After all to err is human, and I’m indeed very human. But throw me a warning when I do something that goes against best practices, that’s fine. Whether I deal with it is something for me to decide. But stopping me from doing what I’m trying to do, because it’s potentially problematic? GTFO with that kinda BS.
I understand the idea. But many people have hugely mistaken beliefs about what the C[++] languages are and how they work. When you write ADC EAX, R13 in assembly, that’s it. But C is not a “portable assembler”! It has its own complicated logic. You might think that by writing ++i, you are writing just some INC [i] ot whatnot. You are not. To make a silly example, writing
int i=INT_MAX; ++i;you are not telling the compiler to produce INT_MIN. You are just telling it complete nonsense. And it would be better if the compiler “prevented” you from doing it, forcing you to explain yourself better.I get what you’re saying. I guess what I’m yelling at the clouds about is the common discourse more than anything else.
If a screw has a slotted head, and your screwdriver is a torx, few people would say that the screwdriver won’t allow them to do something.
Computers are just tools, and we’re the ones who created them. We shouldn’t be submissive, we should acknowledge that we have taken the wrong approach at solving something and do it a different way. Just like I would bitch about never having the correct screwdriver handy, and then go look for the right one.
Yup, I am with you on this one
New copypasta just dropped
I used to love C++ until I learned Rust. Now I think it is obnoxious, because even if you write modern C++, without raw pointers, casting and the like, you will be constantly questioning whether you do stuff right. The spec is just way too complicated at this point and it can only get worse, unless they choose to break backwards compatibility and throw out the pre C++11 bullshit
Depending on what I’m doing, sometimes rust will annoy me just as much. Often I’m doing something I know is definitely right, but I have to go through so much ceremony to get it to work in rust. The most commonly annoying example I can think of is trying to mutably borrow two distinct fields of a struct at the same time. You can’t do it. It’s the worst.
Structs with union members that allow the same place in memory to be accessed either word-wise, byte-wise, or even bit-wise are a god-sent for everyone who needs to access IO-spaces, and I’m happy my C-compiler lets me do it.
#pragma push
Context?
You use it to “pack” bitfields, bytes etc together in structs/classes (wo functions), otherwise the computer usually align every variable on a 32bit boundary for speed.
You don’t need that pragma to pack bitfields.
With say a 3bit int, then a 2bit int and various char, int etc and so on you did have to use the pragma with gcc & visual around 2012 at least
OK, I use the Keil ARM compiler, and never needed to push anything.
Then I’d make a unit test, there is no requirement to do so by the compiler (not even the order).
I’m all for having the ability to do these shenanigans in principle, but prefer if they are guarded in an
unsafeblock.I don’t know which is worse. Using C++ like lazy C, or using C++ like it was designed to be used.
An acquaintance of mine once wrote a finite element method solver entirely in C++ templates.
As it should be. Airbags should go off when you crash, not when you drive near the edge of a cliff.
No need to cast as any types at all just work with bits directly /s
Aand what is wrong with that?
The problem is that it’s undefined behavior. Quake fast inverse square root only works before the types just happen to look that way. Because the floats just happens to have that bit arrangement. It could look very different on other machines! Nevermind that it’s essentially always exactly the same on most architectures. So yeah. Undefined behavior is there to keep your code usable even if our assumptions about types and memory change completely one day.
I actually do like that C/C++ let you do this stuff.
Sometimes it’s nice to acknowledge that I’m writing software for a computer and it’s all just bytes. Sometimes I don’t really want to wrestle with the ivory tower of abstract type theory mixed with vague compiler errors, I just want to allocate a block of memory and apply a minimal set rules on top.
100%. In my opinion, the whole “build your program around your model of the world” mantra has caused more harm than good. Lots of “best practices” seem to be accepted without any quantitative measurement to prove it’s actually better. I want to think it’s just the growing pains of a young field.
