struct FlatHashMap(K, V = void, alias hasher = hashOf, string keyEqualPred = defaultKeyEqualPredOf!(K), Allocator = Mallocator, bool borrowChecked = false, bool useSmallLinearSearch = true, bool usePrimeCapacity = false)
static if(!((is(K == class)) && keyEqualPred == `a is b`))
static if(!(isPointer!K && (keyEqualPred == `a == b` || keyEqualPred == `a is b`)))
=
K