Is there a tab equivalent of std::endl within the standard library?

Question

Using C++, is there an equivalent standard library constant for '\t' like there is for a newline?

Ideally:

std::stringstream ss;
ss << std::tab << "text";

If not, why is this the case?

(I'm aware I can just insert a '\t' but I'd like to sate my curiosity).

Brian Bi · Accepted Answer · 2014-02-27T01:30:29.217

108

No. std::endl isn't a newline constant. It's a manipulator which, in addition to inserting a newline, also flushes the stream.

If you just want to add a newline, you're supposed to just insert a '\n'. And if you just want to add a tab, you just insert a '\t'. There's no std::tab or anything because inserting a tab plus flushing the stream is not exactly a common operation.

edited Feb 27 '14 at 01:30

answered Feb 27 '14 at 01:10

Brian Bi

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@Ksletmo, the sequence inserted by `endl` is always `'\n'`; it has nothing to do with the platform's preferred text-file line ending. – Rob Kennedy Feb 27 '14 at 01:26
3

To put that another way: the newline character `'\n'` is a standard ASCII character just like `'\t'` is. The effect of writing the single character `'\n'` to a file opened in text mode varies by platform. As Rob says, that's nothing to do with `std::endl`, which just writes a character and does a flush. It doesn't know or care what the stream does with that character. – Steve Jessop Feb 27 '14 at 01:58
How is `foo << '\t'` different that `foo << 10` ('\t' is encoded as a 10 in ascii). I want a tab, not a formatted 10. – wcochran Jun 30 '20 at 19:13

score 25 · Answer 2 · answered Nov 24 '16 at 04:45

If you want to add the feature yourself, it would look like this:

#include <iostream>

namespace std {
  template <typename _CharT, typename _Traits>
  inline basic_ostream<_CharT, _Traits> &
  tab(basic_ostream<_CharT, _Traits> &__os) {
    return __os.put(__os.widen('\t'));
  }
}

int main() {

  std::cout << "hello" << std::endl;
  std::cout << std::tab << "world" << std::endl;
}

I don't recommend doing this, but I wanted to add a solution for completeness.

Sly_TheKing · Answer 3 · 2017-06-16T17:03:23.113

4

No.

There are only std::ends (insert null character) and std::flush (flush the stream) output manipulators besides std::endl in ostream include file.

You can find others in ios and iomanip include files. Full list is here

edited Jun 16 '17 at 17:03

answered Feb 27 '14 at 01:14

Sly_TheKing

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score 4 · Answer 4 · edited Nov 24 '16 at 04:18

4

Actually, it is not needed.

Because endl first does the same job of inserting a newline as \n, and then also flushes the buffer.

Inserting \t on a stream does not require to flush it after .

edited Nov 24 '16 at 04:18

sergiol

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answered Feb 27 '14 at 01:27

Pranit Kothari

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Is there a tab equivalent of std::endl within the standard library?

4 Answers4