Integer context keys

We’re looking at different types for context keys. So far, we’ve looked at empty structs (struct{}), and found it to be less than ideal. Today, let’s consider integer context keys. This seems handy, right? type contextKey int const ( KeyUserID int = iota KeyTransactionID KeyMessageID . . . KeyFoo ) Let’s see how it stacks up to our 5 criteria: Must be comparable. ✅ No problem! Use minimal membory. ✅ int doesn’t have as small a memory footprint as struct{}’s zero bytes, but it’s still pretty small.