this post was submitted on 05 Apr 2025
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Programmer Humor

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[–] SpaceNoodle@lemmy.world 46 points 2 years ago* (last edited 2 years ago) (1 children)

If I'm writing C++, I'm usually optimizing for portability over performance, in which case I would prefer std::endl as it would yield the best results regardless of platform; it also keeps the end-of-line character out of other strings, making code just a little cleaner.

\n is for when I'm done pretending that anything that isn't Unix-like is OK, or I'm counting the cycles of every branch instruction.

[–] barubary@infosec.exchange 33 points 2 years ago (2 children)

std::endl provides zero portability benefits. C++ does have a portable newline abstraction, but it is called \n, not endl.

[–] Albbi@lemmy.ca 49 points 2 years ago

Thank you two for demonstrating the image in the post so well.

[–] SpaceNoodle@lemmy.world 7 points 2 years ago (1 children)

No, there's no guarantee that in every context \n is translated portably.

[–] barubary@infosec.exchange 16 points 2 years ago (2 children)

The same is true of std::endl. std::endl is simply defined as << '\n' << std::flush; nothing more, nothing less. In all cases where endl gives you a "properly translated" newline, so does \n.

[–] SpaceNoodle@lemmy.world 7 points 2 years ago (1 children)

Ahhh, I see. Looks like the magic happens somewhere further down in iostream.

[–] AnyOldName3@lemmy.world 4 points 2 years ago

It's controlled by whether the stream's opened in text mode or binary mode. On Unix, they're the same, but on Windows, text mode has line ending conversion.

[–] zenforyen@feddit.org 3 points 2 years ago

Yeah it's an artificial dichotomy based on a popular misconception of what std::endl is and how \n is interpreted.

Ultimately it does not ask about line endings, but about flushing, which is a completely orthogonal question.

[–] jecxjo@midwest.social 22 points 2 years ago (2 children)

They aren't the same thing so the comparison is weird.

endl has a flush which is important when doing something like embedded work or RTOS development. If i was doing multiple lines they all were \n until the last line when i actually want to push the buffer.

Obviously depending on the tuning of the compiler's optimization multiple flushes could be reduced but the goal should always be to write as optimal as possible.

[–] aport@programming.dev 3 points 2 years ago (2 children)

Who in the hell is using iostreams in an RTOS

[–] KeenFlame@feddit.nu 2 points 2 years ago

Several. Probably dozens

[–] jecxjo@midwest.social 2 points 2 years ago

Sometimes you work in a codebase that was decided on by others for reasons you don't know.

[–] UpperBroccoli@lemmy.blahaj.zone 20 points 2 years ago

\n, because I ordered a newline, not a flush.

[–] unlawfulbooger@lemmy.blahaj.zone 17 points 2 years ago (5 children)
[–] vapeloki@lemmy.world 40 points 2 years ago (1 children)

std::endl is used in output streams in C++ to end the line, using the os specific line termination sequence, and flush the buffer.

The later one is a performance issue in many cases, why the use of "\n" is considered preferred

[–] xigoi@lemmy.sdf.org 2 points 2 years ago (2 children)

Don’t most terminals flush the buffer on newline anyway?

[–] ClemaX@lemm.ee 8 points 2 years ago

It is the stream itself that is buffered, so the terminal does not handle the contents until the stream is flushed.

[–] vapeloki@lemmy.world 2 points 2 years ago

Maybe, but there is the internal buffer. Also, most I/O happens in files not consoles

[–] hellfire103@lemmy.ca 10 points 2 years ago* (last edited 2 years ago) (5 children)

Instead of this:

cout << "Hello world.\n";

You can do this:

cout << "Hello world." << endl;
[–] Daedskin@lemm.ee 6 points 2 years ago

The fact that you used the namespace for cout but not for endl inordinately bothers me

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[–] gon@lemm.ee 7 points 2 years ago (2 children)
[–] unlawfulbooger@lemmy.blahaj.zone 11 points 2 years ago (2 children)

Boy am I glad I don’t do C++ anymore. That string handling with the overloaded bitshift operator was wild.

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[–] SqueakyBeaver@lemmy.blahaj.zone 2 points 2 years ago

Alternatively:

https://en.cppreference.com/w/cpp/io/manip/endl

p.s. The site isn't entirely mobile friendly

(I'm a cppref lover tbh)

[–] allywilson@lemmy.ml 3 points 2 years ago

From memory it's a way to declare a line ending after your string.

[–] jaybone@lemmy.zip 2 points 2 years ago

God bless your soul.

[–] GideonBear@lemmy.ml 16 points 2 years ago

#define endl "\n"

[–] scrubbles@poptalk.scrubbles.tech 12 points 2 years ago (1 children)
[–] tourist@lemmy.world 9 points 2 years ago
/* I'm new to this language so just imagine there is a new line here when it prints: */
[–] besselj@lemmy.ca 10 points 2 years ago (2 children)
[–] SpaceNoodle@lemmy.world 20 points 2 years ago (1 children)
[–] xmunk@sh.itjust.works 3 points 2 years ago

Yeah \r gang4lyfe

[–] aport@programming.dev 2 points 2 years ago (1 children)

Are you a modem by any chance?

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[–] xmunk@sh.itjust.works 9 points 2 years ago (1 children)
[–] grandel@lemmy.ml 2 points 2 years ago (1 children)

I like that you added the absolute namespace identifier or whatever its called

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[–] lengau@midwest.social 9 points 2 years ago

os.linesep

Lol jk none of my stuff runs on Windows anyway

[–] pewpew@feddit.it 5 points 2 years ago
[–] savvywolf@pawb.social 5 points 2 years ago
[–] nope@jlai.lu 5 points 2 years ago (2 children)

Environment.NewLine might exist in C#

[–] MrScottyTay@sh.itjust.works 2 points 2 years ago

It might do. I encountered it last week as I needed it for a powershell script. So it exists in that at least

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[–] lnxtx@feddit.nl 4 points 2 years ago

Rebel side \0

[–] bramen49@lemmy.ml 4 points 2 years ago

Well, Java has System.lineSeparator so, maybe no?

[–] dave@feddit.uk 3 points 2 years ago
[–] RandomVideos@programming.dev 2 points 2 years ago

Endl is faster to type

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