How to construct an object derived from class ostream in g++ version 3

How to construct an object derived from class ostream in g++ version 3

[Edwin Chan/Toronto/IBM]

 Here's a test file to show what I really meant.

#include <iostream.h>
class PageStream: virtual public ios, public ostream{
public:
   PageStream();
};
PageStream::PageStream(){}
int main(){return 0;}

This is the error message:

t.cpp: In constructor `PageStream::PageStream()':
t.cpp:11: no matching function for call to `std::basic_ostream<char,
std::char_traits<char> >::basic_ostream()'
/.../torolab.ibm.com/fs/projects/vabld/run/gcc/3.0.3/include/g++-v3/bits/std_ostream.h:177:

candidates are: std::basic_ostream<_CharT, _Traits>::basic_ostream(const
std::basic_ostream<_CharT, _Traits>&) [with _CharT = char, _Traits =
std::char_traits<char>]
/.../torolab.ibm.com/fs/projects/vabld/run/gcc/3.0.3/include/g++-v3/bits/std_ostream.h:67:

std::basic_ostream<_CharT, _Traits>::basic_ostream(std::basic_streambuf
<_CharT, _Traits>*) [with _CharT = char, _Traits = std::char_traits<char>]

What is required to match the function call? Is there something missing in
the constructor?

Thank you for your acknowledgement.

Re: How to construct an object derived from class ostream in g++ version 3

[Claudio Bley]

>>>>> "Edwin" == Edwin Chan/Toronto/IBM <edwinc@ca.ibm.com> writes:

    Edwin>  Here's a test file to show what I really meant.  #include
    Edwin> <iostream.h> class PageStream: virtual public ios, public
    Edwin> ostream{ public: PageStream(); };
    Edwin> PageStream::PageStream(){} int main(){return 0;}

    Edwin> candidates are: std::basic_ostream<_CharT,
    Edwin> _Traits>::basic_ostream(const std::basic_ostream<_CharT,
    Edwin> _Traits>&) [with _CharT = char, _Traits =
    Edwin> std::char_traits<char>]
    Edwin> /.../torolab.ibm.com/fs/projects/vabld/run/gcc/3.0.3/include/g++-v3/bits/std_ostream.h:67:

    Edwin> std::basic_ostream<_CharT,
    Edwin> _Traits>::basic_ostream(std::basic_streambuf <_CharT,
    Edwin> _Traits>*) [with _CharT = char, _Traits =
    Edwin> std::char_traits<char>]

    Edwin> What is required to match the function call? Is there
    Edwin> something missing in the constructor?

GCC already told you which constructors are available.

You're trying to use the default constructor of class ostream which is
declared protected in its base class basic_ios<>.

You need to use one of the other constructors:

ostream(streambuf*) or ostream(const ostream&)


Claudio