Fix strict weak ordering of Address (#277)

Author: mpenick

cpp-driver/gtests/src/unit/tests/test_address.cpp

@@ -163,3 +163,37 @@ TEST(AddressUnitTest, Hash) {
   set.insert(Address("0.0.0.0", 9041));
   EXPECT_EQ(set.size(), 5u); // Added
 }
+
+TEST(AddressUnitTest, StrictWeakOrder) {
+  { // Family
+    Address a("localhost", 9042);
+    Address b("127.0.0.1", 30002, "a");
+    ASSERT_NE(a, b);
+    ASSERT_TRUE(a < b);
+    ASSERT_FALSE(b < a);
+  }
+
+  { // Port
+    Address a("localhost", 9042, "b");
+    Address b("localhost", 30002, "a");
+    ASSERT_NE(a, b);
+    ASSERT_TRUE(a < b);
+    ASSERT_FALSE(b < a);
+  }
+
+  { // Server name
+    Address a("127.0.0.2", 9042, "a");
+    Address b("127.0.0.1", 9042, "b");
+    ASSERT_NE(a, b);
+    ASSERT_TRUE(a < b);
+    ASSERT_FALSE(b < a);
+  }
+
+  { // Hostname or address
+    Address a("127.0.0.1", 9042, "a");
+    Address b("127.0.0.2", 9042, "a");
+    ASSERT_NE(a, b);
+    ASSERT_TRUE(a < b);
+    ASSERT_FALSE(b < a);
+  }
+}

cpp-driver/src/address.cpp

@@ -100,11 +100,10 @@ bool Address::equals(const Address& other, bool with_port) const {
 }
 
 bool Address::operator<(const Address& other) const {
-  if (family_ < other.family_) return true;
-  if (port_ < other.port_) return true;
-  if (server_name_ < other.server_name_) return true;
-  if (hostname_or_address_ < other.hostname_or_address_) return true;
-  return false;
+  if (family_ != other.family_) return family_ < other.family_;
+  if (port_ != other.port_) return port_ < other.port_;
+  if (server_name_ != other.server_name_) return server_name_ < other.server_name_;
+  return hostname_or_address_ < other.hostname_or_address_;
 }
 
 String Address::hostname_or_address() const {