Not at all. If I get floats from $somewhere, I might want to index them into a hash data structure without creating a huge sparse array. If you assume float n

Not at all. If I get floats from $somewhere, I might want to index them into a hash data structure without creating a huge sparse array. If you assume float numbers have "identity" such that, whatever the precision, "x == x" always holds (other than NaN), then this is a perfectly valid thing to want.