// { dg-do compile }// Tests if case ranges (a GNU extension) correctly emit messages// about overlapping ranges.// { dg-options "" }const int low = -2;const int high = 15;template <typename T>T f2 (T i){  switch (i)  {    case low ... high : return i + 1;  // { dg-error "" }    case 5 : return i + 2;             // { dg-error "duplicate" }    default : return 0;  }}int f (int i){  switch (i) {    case 1 ... 10: return i + 1;       // { dg-error "" }    case 3 ... 5 : return i + 3;       // { dg-error "duplicate" }    default: return f2 (i);            // { dg-error "" }  }}