Compilare: main.cpp: In function 'symbol parse_next()': main.cpp:28:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | if(idx >= s.size()) { | ~~~~^~~~~~~~~~~ main.cpp:44:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | while(idx < s.size() && isdigit(s[idx])) { | ~~~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:91:28: warning: suggest parentheses around '&&' within '||' [-Wparentheses] 91 | while(ops.size() > 0 && ops.back() == 'm' || ops.back() == 'M') { | ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ main.cpp:104:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 104 | for(int i = 0; i < vals.size(); i++) { | ~~^~~~~~~~~~~~~ main.cpp:108:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 108 | for(int i = 0; i < ops.size(); i++) { | ~~^~~~~~~~~~~~