Hi,

 

How can I read in a from a stream when I don’t know the exact type I will be getting?  All objects I receive will derive from the same base class, but I won’t know when I receive the stream what the derived type will be and therefore I can’t create it in advance (like in the docs).

 

class base

{

…

}

 

class derived1 : public base

{

…

}

 

class derived2 : public base

{

…

}

 

int main()

{

    // Get a stream from somewhere

    boost::archive::binary_iarchive ia( instream );

 

    base b0;

    derived1 d1;

    derived2 d2;

    is >> // derived1 or derived2???

}

 

ryan.fowler@thomsonreuters.com
thomsonreuters.com