By now we’ve looked at empty structs (struct{}), and integers as possible context key types. Today, let’s consider string context keys. type contextKey string const ( KeyUserID = "user_id" KeyTransactionID = "transaction_id" KeyMessageID = "message_id" ) How does this stack up against our 5 criteria? Must be comparable. ✅ Check. Use minimal memory. ✅ Using a string will typically use a bit more memory than an integer (typically 32 bytes vs 16), but still quite minimal.
