I'd do it like this:
import std.algorithm : map;
pars.map!((part) => part.toString) // Turn them to strings
.join(" ").writeln; // Join them.
You can shorten this by using std.conv.to. Also keep in mind that `join` will allocate, but `std.algorithm.joiner` will not.
Ex.
//No allocations done, not even to!string
pars.map!(to!string).joiner(" ").writeln;
