import std.stdio;

​

struct S {

  int x;

  int y;

}

​

auto setValue(ref S s, string field, int value) {

  foreach (fieldName; __traits(allMembers, S)) {

    if (fieldName == field) {

      __traits(getMember, s, fieldName) = value;

      break;

    }

  }

}

​

void main() {

  S s;

  s.setValue("x", 5);

  s.setValue("y", 25);

  writeln(s);

}

​