From: "bowman" Newsgroups: comp.os.msdos.djgpp References: <3B7CEDE9 DOT 17D0DCC9 AT hotmsil DOT com> <3B7F0AB9 DOT 5080903 AT operamail DOT com> Subject: Re: Problem compiling c++ Lines: 28 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Message-ID: Date: Sat, 25 Aug 2001 10:53:59 -0600 NNTP-Posting-Host: 208.4.224.32 X-Trace: newsfeed.slurp.net 998758441 208.4.224.32 (Sat, 25 Aug 2001 11:54:01 CDT) NNTP-Posting-Date: Sat, 25 Aug 2001 11:54:01 CDT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com "Sahab Yazdani" wrote in message news:3B7F0AB9 DOT 5080903 AT operamail DOT com... > > > using namespace std; > ^^^^^^^^^^^^^^^^^^^^^^ > what does this do?? I have a bunch of books on C++, but i've never run > across this line b4. you might want to update your C++ references. Try Stroustrup's 3rd Edition. A current C++ compiler will reject : cout << "Hello World" << endl; and require you to qualify the references to the std namespace as: std::cout << "Hello World" << std::endl; the 'using namespace std;' tells the compiler that you are, indeed, pulling in functions from the std package and you will not have to qualify each usage. While this is handy, it negates the attempt to reduce namespace pollution, and should be applied sparingly. For instance, if you had two packages providing the function 'do_it()', qualifying them as pkg1::do_it() and pkg2::do_it() avoids the compiler errors and also removes ambiguity for the human reader.