[c++] auto

#include <iostream>
using namespace std; 

int main()
{
	string s = "Keep out!";
	for(auto &c : s){/**/}
	return 0;
}

g++     test.cpp   -o test
test.cpp: In function ‘int main()’:
test.cpp:9:12: error: ISO C++ forbids declaration of ‘c’ with no type [-fpermissive]
  for(auto &c : s){/**/}
            ^
test.cpp:9:16: error: range-based ‘for’ loops are not allowed in C++98 mode
  for(auto &c : s){/**/}
                ^
make: *** [test] Error 1

make test -std=c++11

g++ test.cpp -o test -std=c++11