shift right with >>>?

[dennis luehring]

http://rosettacode.org/wiki/Variable-length_quantity#D

ulong value = 0x100;
ubyte[] v = [0x7f & value];
for (ulong k = value >>> 7; k > 0; k >>>= 7)
{
   v ~= (k & 0x7f) | 0x80;
   if (v.length > 9)
   {
     throw new Exception("Too large value.");
   }
}
v.reverse();

while porting this to D i stumple accross the ">>>" - why is that 
allowed in D?