Summary: Problems in std.range documentation
isRandomAccessRange: Inconsistency between description and sample code. The
description indicates the criteria for random-access is "forward or infinite",
but the sample code indicates the criteria is "forward and (bidirectional or
advance: "The pass of r into drop is by reference..." 'drop' should be
'advance' (or maybe the other way around?)
retreatN: "The pass of r into advanceRight is by reference..." 'advanceRight'
should be 'retreatN' (or maybe the other way around?)