1 import std.stdio;
 2 
 3 struct person {
 4     char[] first_name = "(none)";
 5     char[] last_name  = "(none)";
 6     int    id         = -1; 
 7     char[] zipcode    = "00000";
 8 }
 9 
10 void main(char[][] args)
11 {
12     person[10] population;
13     
14     population[2].first_name = "fred";
15     population[2].id         = 1001;
16     population[2].zipcode    = "27502";
17 
18     population[3].first_name = "barney";
19     population[3].id         = 1002;
20     population[3].zipcode    = "27501";
21     
22     foreach (p; filtered(population)) {
23         writefln(p.zipcode);
24     }
25 }
26 
27 struct zips { int id; char[] zipcode; }
28 
29 zips[] filtered(person[] population) {
30     zips[] retval;
31 
32     foreach (p; population) {
33 	if (p.id >= 0) {
34 	    retval ~= zips(p.id, p.zipcode);
35 	}
36     }
37 
38     return retval;
39 }