No. This kind of class extension is not possible in C++
. But you can inherit a class from the original source file and add new functions in your source file.
//Abc.h
class Abc {
void methodOne();
void methodTwo();
};
//Abc+Ext.h
class AbcExt : public Abc {
void methodAdded();
};
You can then call methods as following:
std::unique_ptr<AbcExt> obj = std::make_unique<AbcExt>();
obj->methodOne(); // by the virtue of base class
obj->methodAdded(); // by the virtue of derived class