Can anyone figure this out?

[John Barry]

This short program compiles and links just fine.

#include "corba.h"

class MyClass
{
public:
void mytest(std::istream &strm)
{
VISistream v(strm);
}
};

int main()
{
return 0;
}

However, if the MyClass::mytest is implemented outside of the class
declaration instead of inside, for instance

void MyClass::mytest(std::istream &strm)
{
VISistream v(strm);
}

Then the program fails to link with this error:

ERROR: Undefined symbol:
.VISistream::VISistream(std::basic_istream<char,std::char_traits<char>
>&)

I'm using Visibroker 6 and Visual Age C++ under AIX 5.2. Any ideas?