c++ STL cout source code

Question

I want to see source code of STL std::cout function. I looked at iostream, but I've seen only "extern cout". So, I guess that it's defined somewhere in the library.

I downloaded source code from official site

I extracted it and did:

sh@sh-R528-R728:~/desktop/stl$ grep -F * | grep "cout"

but I got nothing.

What am I doing wrong? Where is the source code?

may be, I just want to see how it works. I would to like to compare printf and cout inside. — Tebe, May 20 '12 at 19:08
`std::cout` is not a function, it's an object. That aside, try your luck with [libc++](http://libcxx.llvm.org/) in iostream.cpp. — Xeo, May 20 '12 at 19:10
`operator<<` is what you are probably interested in. Search for that. — Benjamin Lindley, May 20 '12 at 19:10
or probably you might be interested in looking out for ostream. — axiom, May 20 '12 at 19:11
@shbk - Most of the source is templates that you can find in the headers. `std::cout` is just an object of type `ostream`. You will find all of that in `` provided with your compiler. — Bo Persson, May 20 '12 at 19:19
Also note this from the SGI page: "Last updated: 8-June-00". — Bo Persson, May 20 '12 at 19:21
it's sad for me, but there is only one entry of cout in ostream file - in comments. I am confused. I feel that I only go around. — Tebe, May 20 '12 at 19:27
`std::cout` is not a function; it is an instance of `std::ostream`. It is not part of the SGI STL, but of the C++ Standard Library. This is why everybody calling [parts of] the Standard Library "the STL" is harmful. — Lightness Races in Orbit, Feb 03 '13 at 21:27

score 9 · Answer 1 · edited May 12 '15 at 16:43

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If you happen to be using GCC, then libstdc++ is your C++ library. Its sources can be found on gcc.gnu.org. cout is defined on line 58 of src/c++98/globals_io.cc.

edited May 12 '15 at 16:43

Gavin Haynes

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answered May 20 '12 at 19:31

Fred Foo

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score 7 · Accepted Answer · edited May 21 '12 at 15:59

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cout is not part of the STL, so you won't find the source for cout in the STL source.

You probably want to look for the source for your C++ standard library, which was based on the STL, but also contains iostreams. Where that is depends on what platform you're using.

edited May 21 '12 at 15:59

Mooing Duck

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answered May 20 '12 at 19:13

Alan Stokes

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well, nice as I see here http://www.cplusplus.com/reference/ . The header of cout is ostream. I cannot find realization of cout in ostream. Could you plz give a tip how to find it? I sought word "cout" and I've founf it only in comments. – Tebe May 20 '12 at 19:23
@shbk: Alan is referring to the fact that the C++ standard library and the STL are different things. However, many many people call the C++ standard library "STL" since it originated as a copy of the STL Library. The original STL library did not contain streams. – Mooing Duck May 20 '12 at 19:25
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@shbk: cout should not be in ostream, it should be in iostream. But as was said in the comments, cout is an object, not a function. So finding cout isn't going to tell you how it works. You need to find its class(ostream) and the functions of that class. – Benjamin Lindley May 20 '12 at 19:26
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@MooingDuck: the C++ standard library did not originate as a *copy* of the STL; rather, it subsumed large parts of the STL (but not all of it, even in C++11). – Fred Foo May 20 '12 at 19:29
it's nice. But in I can find only this: extern ostream cout; ///< Linked to standard output – Tebe May 20 '12 at 19:29
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@shbk: **FORGET ABOUT COUT. IT IS NOT WHAT YOU ARE LOOKING FOR. READ THE THINGS WE ARE SAYING.** – Benjamin Lindley May 20 '12 at 19:31
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@Mooing it's not just that - the OP's link points to the SGI STL, which definitely doesn't include `cout`. – Alan Stokes May 20 '12 at 19:33

score 2 · Answer 3 · answered May 20 '12 at 19:34

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std::cout is not a function, it is a instance of std::ostream (interface description) that is tied to standard output.

If you are using gcc/libstdc++, have a blast browsing its source code online

answered May 20 '12 at 19:34

Benoît

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Better: [gcc.gnu.org/git/?p=gcc.git&a=search&h=HEAD&st=grep&s=\bcout\b&sr=1](http://gcc.gnu.org/git/?p=gcc.git&a=search&h=HEAD&st=grep&s=\bcout\b&sr=1) – kennytm May 21 '12 at 17:37

c++ STL cout source code

3 Answers3

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