Compilare: main.cpp: In function 'int main()': main.cpp:48:40: warning: loop variable 'pir' of type 'const std::pair<char, int>&' binds to a temporary constructed from type 'std::pair<const char, int>' [-Wrange-loop-construct] 48 | for (const pair<char,int>& pir : aux2) { | ^~~ main.cpp:48:40: note: use non-reference type 'const std::pair<char, int>' to make the copy explicit or 'const std::pair<const char, int>&' to prevent copying