main.cpp: In function 'int main()':
main.cpp:21:5: error: redefinition of 'int main()'
 int main() {
     ^~~~
In file included from main.cpp:17:0:
figure.h:92:5: note: 'int main()' previously defined here
 int main() {
     ^~~~
figure.h: In function 'std::shared_ptr<Figure> CreateFigure(std::istringstream&)':
figure.h:90:1: error: control reaches end of non-void function [-Werror=return-type]
 }
 ^
cc1plus: all warnings being treated as errors