Tried on g++.EXE (tdm-1) 5.1.0 and g++ (GCC) 5.1.1 20150618 (Red Hat 5.1.1-4)

Compile the following minimal source code with command line 'g++ -std=c++11 t.cpp'

#include <utility>
using namespace std;
struct A {
    pair<int, int> values[2000000];
};
int main() {
  A x;
  return 0;
}

Compilation hangs for a very long time.