Question

In order to simplify matters, I wrote this class StringStream in a Notifications.h file:

namespace A {
namespace B {
namespace C {

extern std::locale g_classicLocale;
class StringStream : public virtual std::ostringstream
{
 public:
        StringStream() { imbue(g_classicLocale); }
        virtual ~StringStream() {};
};

} // namespace C
} // namespace B
} // namespace A

Now, I’m trying to use StringStream in my DBNotification.cpp file:

 #include "Notifications.h"

 namespace A{
 namespace B{
 namespace C{

         DBNotification::DBNotification(){

         }
         DBNotification::~DBNotification(){

         }
         StringStream DBNotification::getValues(){

            // do some work and return me a StringStream Object
         }
 } // C
 } // B
 } // A

When I build the source code, I get:

/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/ios_base.h: In copy constructor 'std::basic_ios<char, std::char_traits<char> >::basic_ios(const std::basic_ios<char, std::char_traits<char> >&)':
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/ios_base.h:779: error: 'std::ios_base::ios_base(const std::ios_base&)' is private
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/iosfwd:55: error: within this context
../Notifications.h: In copy constructor 'A::B::C::StringStream::StringStream(const A::B::C::StringStream&)':
../Notifications.h:49: note: synthesized method 'std::basic_ios<char, std::char_traits<char> >::basic_ios(const std::basic_ios<char, std::char_traits<char> >&)' first required here
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/streambuf: In copy constructor 'std::basic_stringbuf<char, std::char_traits<char>, std::allocator<char> >::basic_stringbuf(const std::basic_stringbuf<char, std::char_traits<char>, std::allocator<char> >&)':
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/streambuf:781: error: 'std::basic_streambuf<_CharT, _Traits>::basic_streambuf(const std::basic_streambuf<_CharT, _Traits>&) [with _CharT = char, _Traits = std::char_traits<char>]' is private
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/iosfwd:71: error: within this context
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/iosfwd: In copy constructor 'std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >::basic_ostringstream(const std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >&)':
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/iosfwd:79: note: synthesized method 'std::basic_stringbuf<char, std::char_traits<char>, std::allocator<char> >::basic_stringbuf(const std::basic_stringbuf<char, std::char_traits<char>, std::allocator<char> >&)' first required here

Could someone let me know what’s going on?

Answer 1

Generally streams cannot be copied. Your function DBNotification::getValues() returns a stream object.

Please see this answer