Introduce enum ServiceFlags for service flags

src/protocol.h

@@ -223,7 +223,9 @@ extern const char *FEEFILTER;
 const std::vector<std::string> &getAllNetMessageTypes();
 
 /** nServices flags */
-enum {
+enum ServiceFlags : uint64_t {
+    // Nothing
+    NODE_NONE = 0,
     // NODE_NETWORK means that the node is capable of serving the block chain. It is currently
     // set by all Bitcoin Core nodes, and is unset by SPV clients or other peers that just want
     // network services but don't provide them.
@@ -251,7 +253,7 @@ class CAddress : public CService
 {
 public:
     CAddress();
-    explicit CAddress(CService ipIn, uint64_t nServicesIn);
+    explicit CAddress(CService ipIn, ServiceFlags nServicesIn);
 
     void Init();
 
@@ -267,13 +269,15 @@ public:
         if ((nType & SER_DISK) ||
             (nVersion >= CADDR_TIME_VERSION && !(nType & SER_GETHASH)))
             READWRITE(nTime);
-        READWRITE(nServices);
+        uint64_t nServicesInt = nServices;
+        READWRITE(nServicesInt);
+        nServices = (ServiceFlags)nServicesInt;
         READWRITE(*(CService*)this);
     }
 
     // TODO: make private (improves encapsulation)
 public:
-    uint64_t nServices;
+    ServiceFlags nServices;
 
     // disk and network only
     unsigned int nTime;