Compilare: main.cpp: In function 'void eval1()': main.cpp:18:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(idx < sir.length() && sir[idx] == ','){ ~~~~^~~~~~~~~~~~~~ main.cpp: In function 'void eval2()': main.cpp:28:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(idx < sir.length() && ((sir[idx] >= 'a' && sir[idx] <= 'z') || (sir[idx] >= '0' && sir[idx] <= '9'))){ ~~~~^~~~~~~~~~~~~~ main.cpp:37:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(idx < sir.length() && ((sir[idx] >= 'A' && sir[idx] <= 'Z') || (sir[idx] >= '0' && sir[idx] <= '9'))){ ~~~~^~~~~~~~~~~~~~