Unget Puns

Problems with ungets and possible getop. I'm using '!' to avoid handling '\0' and EOF. I really look forward to feedback.

https://pastebin.com/fSaGEK2q

I'm doing some C++ work again for the first time in many years, and struggling with very basic file IO. In particular, I can't get unget() or putback() to work on a std::ifstream.

Here's a basic example to illustrate my problem. I have a file named test.txt with the following contents:

test test test

I'm reading this file with the following C++ code:

#include <fstream>
#include <iostream>

int main() {

   std::ifstream is("test.txt");
   char c;

   // Following line prints "got t, offset 1", as expected
   std::cout << "got " << (char)is.get() << ", offset " << is.tellg() << std::endl;

   // Following line prints "got e, offset 2", as expected
   std::cout << "got " << (char)is.get() << ", offset " << is.tellg() << std::endl;

   // Try to unget the last character
   is.unget();

   // ... but this fails. Why?
   if (is.fail()) {
      std::cout << "Something went wrong!" << std::endl;
   }

   // Following line should have printed "got e, offset 2" again.
   // The actual output is "got ?, offset -1".
   std::cout << "got " << (char)is.get() << ", offset " << is.tellg() << std::endl;

   return 0;
}

This works perfectly well until the call to unget(), as explained in the comments in the code above. The actual program output looks like this:

got t, offset 1
got e, offset 2
Something went wrong!
got ?, offset -1

An equivalent example reading from a std::istringstream instead of a std::ifstream works perfectly well.

Am I doing something wrong, or does unget() simply not work for file streams? Of course it's not terribly hard to work around the problem by using peek before I get or by manually remembering the last character read, but I'd like to know if there is some trivial way to make unget() working.

And now there's only dust..

Phil

Sudden Lee

Go post NSFW jokes somewhere else. If I can't tell my kids this joke, then it is not a DAD JOKE.

If you feel it's appropriate to share NSFW jokes with your kids, that's on you. But a real, true dad joke should work for anyone's kid.

Mods... If you exist... Please, stop this madness. Rule #6 should simply not allow NSFW or (wtf) NSFL tags. Also, remember that MINORS browse this subreddit too? Why put that in rule #6, then allow NSFW???

Please consider changing rule #6. I love this sub, but the recent influx of NSFW tagged posts that get all the upvotes, just seem wrong when there are good solid DAD jokes being overlooked because of them.

Thank you,

A Dad.

So far nobody has given me a straight answer

..... Will get a reward.

Well, toucan play at that game.

Windows

Martin Freeman, and Andy Serkis.

They also play roles in Lord of the Rings.

I guess that makes them the Tolkien white guys.

She said apple-lutely

'Eye-do'

This is my first post pls don't kill me lol.

The people in the comment section is why I love this subreddit!!

Cred once again my sis wants credit lol

Keep in mind, my son is 4 years old, so everything is an original to him.

I had to work late into the evening yesterday, and he was just going to bed when I got home. I had left home for the office nearly 14 hours prior, had a long day, lots of meetings, traffic, etc.

When I walked through the door, I was exhausted, run down, and starving. My wife hugged me and asked how my day was, and I replied, "Done. It was a good day, but has got me exhausted. I just want to grab a bite and go to bed. I'm hungry."

From my son's bedroom, I hear him shout, "Hi Hungry! Nice to meet you!"

Not only did it make me laugh, but I completely forgot about how hungry and tired I was. I went to his bedroom, and we laughed together about it. It was exactly what I needed.

Edit: Thanks for all the awards, kind strangers! I'll let my son know y'all enjoyed his joke too!

I heard parents named their children lance a lot.

First post please don't kill me

Edit: i went to sleep and now my inbox is dead, thank you kind strangers for the awards!

Japan.

"No, the regular kind!" I laughed.

second hand stores!

it's Hans free now..

Old Neeeeiiiiighvy

10+10 is twenty and 11+11 is twenty too

A buck-an-ear!

I Thank ye kind Matey for the booty! I be truly overwhelmed! Thank you!

Holy cow! Thank you everyone for the upvotes and awards! I wasn’t expecting this!

and not:

He should have a good vowel movement. His next diaper change could spell disaster though.

Making it all the way home and realizing that they forgot one of the containers:

Riceless

That was the punchline