Compilare: main.cpp: In function 'int eval(std::string)': main.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for(int i = 0; i < s.size(); i++) | ~~^~~~~~~~~~ main.cpp:37:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | while(i < s.size() && isdigit(s[i])) | ~~^~~~~~~~~~ main.cpp: In function 'int operatie(int, int, char)': main.cpp:16:1: warning: control reaches end of non-void function [-Wreturn-type] 16 | } | ^