Package fastinteger is designed to provide a very primitive implementation of a hash map for unsigned integer keys and values. It is designed to have existence checks and insertions that are faster than Go's native implementation. Like Go's native implementation, FastIntegerHashMap will dynamically grow in size.

Current benchmarks on identical machine against native Go implementation:

BenchmarkInsert-8	   10000	    131258 ns/op
BenchmarkGoMapInsert-8	   10000	    208787 ns/op
BenchmarkExists-8	  100000	     15820 ns/op
BenchmarkGoMapExists-8	  100000	     16394 ns/op
BenchmarkDelete-8	  100000	     17909 ns/op
BenchmarkGoDelete-8	   30000	     49376 ns/op
BenchmarkInsertWithExpand-8	   20000	     90301 ns/op
BenchmarkGoInsertWithExpand-8	   10000	    142088 ns/op

This performance could be further enhanced by using a better probing technique.