cerr not defined

[LLeweLLyn Reese]

shane@shaneroberts.com writes:

> Bjorn,
> thank you, things are beginning to become clear.
> 
> It would appear that there was an error in the Stroustrup book

It's not an error. It's explained in section 3.3, The Standard Library
    Namespace (pg 46-7 in the paperback version), that Stroustrup
    omits repettitive #includes and std:: qualifications, in the
    interest of clarity.

> where "std::" was left off "cerr" so that it should have been:
> std::cerr << P << ' ' << P2 << '\n';
> 
> for emitting the error message.
> 
> This would have placed cerr in the std namespace which is 
> where<fstream> places it as opposed to <fstream.h>.
> 
> Since I am new to g++ and C++ can anyone clue me into when
> C++ standards changed,

Chapter 1 of the Stroustrup book contians some useful/interesting
    historical information of this sort. The standard itself hasn't
    changed since september 1998, when it was finalized. A round of
    minor corrections, called a TC, should come by this year or next,
    but no major changes will be in it.

> and g++ header files were 
> relocated/changed?

http://gcc.gnu.org/releases.html

If you follow the links you'll get release notes for each gcc release.
    The big change was 2.95.x => 3.x ; 2.95.x accepted std::, but treated
    it as an alias for the global namespace, and had all standard
    library names in the global namespace. 3.0 properly enforced
    std::, and had all the appropriate standard library names in the
    std:: namespace. Also, 2.95.x had older, non-compliant iostreams,
    while 3.x has new iostreams.

> I just need to get my bearings so I know how to distinquish between
> "old" and "new".
[snip]

In the case of gcc, the standard headers with no suffix
    (e.g. <iostream>, <fstream>, etc) are new, and try to be
    conformant with standard C++, put all names in std::, have
    templated streams, etc. The headers with a .h suffix are old, modeled
    on older C++ ideas, like the ARM (1990), do not have namespace
    std:: or templated streams, etc.