You shouldn't be using 32-bit indices on x64, that defeats the
whole
point of x64.
As of .NET 4.5, 64bit array indexes are supported as well.
http://msdn.microsoft.com/en-us/library/hh285054.aspx
Don't forget that we're talking about a *hashtable* here. If a
.NET hashtable used 64-bit indexes (or pointers) it would require
8-12 bytes more memory per entry, specifically 32 bytes total,
including overhead, if the key and value are 4 bytes each.
An in-memory hashtable that requires 64-bit indexes rather than
32 bits would have to contain over 4 billion entries which would
take at least 128 GB of RAM, assuming 8 bytes for each key-value
pair!!! In fact it's worse than that, as the dictionary grows by
size-doubling and contains a certain amount of unused entries at
the end.
No thanks, I'd rather save those 8 bytes and accept the 4 billion
limit, if you don't mind.
