【C++】cpp compiler warning (g++ hoge.cpp) range-based for loop is a C++11 extension

answer_abc114_c.cpp:46:16: warning: range-based for loop is a C++11 extension [-Wc++11-extensions]
    for(char c : s) {
               ^
1 warning generated.

I changed from

g++ hoge.cpp

to

g++ -std=c++14 hoge.cpp