Red-black tree would spare a machine word per node, because a red-black tree
doesn't need depth information. 
Hence the reason is either historical or a space/speed trade-off (comparing
two depths may be faster than pattern matching). 
 
Regards,
 
damien guichard 
Hi, list, 


Just from the curiosity, why balanced binary trees used in Set and Map are
AVL-trees, not their alternative, say, red-black trees?  Is there a deep
reason for it, or just a historical one?


Best,
-- 

Yoriyuki Yamagata
http://yoriyuki.info/