dynamic_cast should be what you are looking for.

dynamic_cast should be what you are looking for.

EDIT:

DerivedType m_derivedType = m_baseType; // gives same error 

The above appears to be trying to invoke the assignment operator, which is probably not defined on type DerivedType and accepting a type of BaseType.

DerivedType * m_derivedType = (DerivedType*) & m_baseType; // gives same error 

You are on the right path here but the usage of the dynamic_cast will attempt to safely cast to the supplied type and if it fails, a NULL will be returned.

Going on memory here, try this (but note the cast will return NULL as you are casting from a base type to a derived type):

DerivedType * m_derivedType = dynamic_cast<DerivedType*>(&m_baseType); 

If m_baseType was a pointer and actually pointed to a type of DerivedType, then the dynamic_cast should work.

Hope this helps!