Many garbage collectors use the same idea (and manage it automatically), with two or three different generations:http://en.wikipedia.org/wiki/Garbage_collection_%28computer_science%29#Generational_GC_.28ephemeral_GC.29Bye, bearophile
The problem with GC is that it doesn't know which is temporary and which is not, so it has to traverse tree to determine that. Allocators in my opinion should let user specify explicitly the temporaries.
