Compilare: user.cpp: In function ‘int main()’: user.cpp:22:24: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] out<<euclid(a,b)<<'\n'; ^ user.cpp:12:14: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] r=a%b; ^ user.cpp:20:11: note: ‘b’ was declared here int a,b,n; ^