Heap: container or range?

[Sean Kelly]

I don't know if it matters, but I added the heap routines to Tango 
because I wanted heapsort, so they kind of came for free.  Perhaps a key 
distinction between ranges and algorithms is that algorithms may mutate 
the underlying data, but ranges may not?  I've been trying to think of 
another example of a mutating range and I haven't come up with one 
yet... unless you consider input ranges mutating, I suppose.


Sean