I want to demonstrate several ways of building multi-file C++ projects.

You do know how to just compile the *.cpp files already.

g++ main.cpp teacher.cpp student.cpp monk.cpp -o the_world
./the_world

That will do the job. But now I want to demonstrate creating object files, *.o:

g++ -c teacher.cpp
g++ -c student.cpp
g++ -c monk.cpp
g++ -c main.cpp
g++ main.o teacher.o student.o monk.o -o the_world
./the_world

Finally we can use a Makefile:

make
./the_world

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