c++ - Error in passing a map by reference to a function -

i want pass map reference function. here code:

void test(map<int, double *> &a);  int main(){     map<int, double *> a;     test(a);     cout << a[1][1] << endl;     return 0; }  void test(map<int, double*> &a) {     double red[] = {1.1, 2, 3};     a[1] = red; } 

the problem that, a[1][1] supposed 2. however, when execute program, gives big number 1.73e120 !!!

double red[] = {1.1, 2, 3};  

has automatic storage duration. means when function returns no longer valid.

you should this

void test(map<int, double*> &a) {     double *red = new double[3];     // fill red.     a[1] = red; }