Got the trivial situation: some c++ code has to be exported statically to other language project via compiling ‘.obj’ files.

At c++ side: the declaration and implementation are classically separated between ‘.h’ and ‘.cpp’ files.

Simple example:

dummy.h

#ifndef dummy_h
#define dummy_h

namespace D {
    void doDummy(); // implementation in 'dummy.cpp'
    
    void doDummyX()
    {
        // do smth
        return;
    };
}

#endif //dummy_h

dummy.cpp

#include "dummy.h"

void D::doDummy() // declared in 'dummy.h'
{
    // do smth
    return;
};

exporttest.cpp

#include "dummy.h"

extern "C" void __stdcall funcTest()
{
    D::doDummy(); // declared in 'dummy.h', implementation in 'dummy.cpp'
    D::doDummyX(); // declaration & implementation in 'dummy.h'
    return;
};

Is there any fast tweak to make compiler include the implementation of function doDummy to corresponding ‘dummy.obj’ file?

Obviously, two ‘.obj’ files are compiled: ‘dummy.obj’ and ‘exporttest.obj’. The problem is none of them contains the implementation binary of doDummy.

I understand that moving implementation of function doDummy directly to “dummy.h” from “dummy.cpp” solves the problem. But this is not the way out in scope of project.
dummy.h

#ifndef dummy_h
#define dummy_h

namespace D {
    void doDummy()
    {
        // do smth
        return;
    };
}

#endif //dummy_h

Also, want to avoid expansion of ‘.h’ with ‘.cpp’ like:
dummy.h

#ifndef dummy_h
#define dummy_h

namespace D {
    void doDummy();
}

#include "dummy.cpp" // expand with implementation (.hpp)

#endif //dummy_h

PS: I know there is a lot info on this topic, BUT I appreciate a minimal workaround with least modifications.