Why does g++ take much longer to compile

g++ version is 5.3.0.

#include <algorithm>
int main() {
    return 0;
}

test$ time g++ test.cpp

real    0m0.203s
user    0m0.073s
sys     0m0.031s

test$ time g++ test.cpp --std=c++11

real    0m0.761s
user    0m0.554s
sys     0m0.130s

Similar results over multiple attempts.