conver BigInt to string

[bearophile via Digitalmars-d-learn]

Namal:

> Hello I am trying to convert BigInt to string like that while 
> trying to sort it:

void main() {
     import std.stdio, std.algorithm, std.conv, std.bigint, 
std.string;

     auto n = 17.BigInt ^^ 179;
     n.text.dup.representation.sort().release.assumeUTF.writeln;
}

Bye,
bearophile