Re: Correct vesion (Re: Clone an object with an abstract base class)

JiiPee <no@notvalid.com> wrote in news:2PK%v.461970$177.56098@fx04.am4:


Here it goes. Assume that the build process checks out and builds
projects one-by one, in the order specified somewhere else (I have used
such a process for many years in the past), to avoid any fancy ideas of
including b.h in the base library (which would by all wrong conceptually
anyway).

// base library (DLL)
// a.h
class A {
public:
    virtual ~A() {}
    virtual A* clone() const = 0;
};

void foo(A* x);

// a.cpp
void foo(A* x) {
    A* y = x->clone();
    delete y;
}

// -------------------------------------

// extension library (DLL) - link to base library
// b.h
//#include <BaseLibrary/a.h>

class B: public A {
public:
    virtual B* clone() const override;
};

// b.cpp
B* B::clone() const {
    return new B(*this);
}

// -------------------------------------

// main program - link to base library and extension library
// main.cpp

//#include <BaseLibrary/a.h>
//#include <Extensionlibrary/b.h>

int main() {
    A* x = new B();
    foo(x);
    delete x;
}