Inline short, often-called, rarely-changed basic CNetAddr getters

and make them nodiscard.

Member functions containing a few lines of code are usually inlined, either
implicitly by defining them in the declaration as done here, or declared inline.

References
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rf-inline
https://google.github.io/styleguide/cppguide#Inline_Functions
https://www.ibm.com/docs/en/i/7.1?topic=only-inline-member-functions-c

Author: jonatack

src/netaddress.cpp

@@ -309,10 +309,6 @@ bool CNetAddr::IsBindAny() const
     return std::all_of(m_addr.begin(), m_addr.end(), [](uint8_t b) { return b == 0; });
 }
 
-bool CNetAddr::IsIPv4() const { return m_net == NET_IPV4; }
-
-bool CNetAddr::IsIPv6() const { return m_net == NET_IPV6; }
-
 bool CNetAddr::IsRFC1918() const
 {
     return IsIPv4() && (
@@ -400,22 +396,6 @@ bool CNetAddr::IsHeNet() const
     return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x04, 0x70});
 }
 
-/**
- * Check whether this object represents a TOR address.
- * @see CNetAddr::SetSpecial(const std::string &)
- */
-bool CNetAddr::IsTor() const { return m_net == NET_ONION; }
-
-/**
- * Check whether this object represents an I2P address.
- */
-bool CNetAddr::IsI2P() const { return m_net == NET_I2P; }
-
-/**
- * Check whether this object represents a CJDNS address.
- */
-bool CNetAddr::IsCJDNS() const { return m_net == NET_CJDNS; }
-
 bool CNetAddr::IsLocal() const
 {
     // IPv4 loopback (127.0.0.0/8 or 0.0.0.0/8)

src/netaddress.h

@@ -162,8 +162,8 @@ class CNetAddr
     bool SetSpecial(const std::string& addr);
 
     bool IsBindAny() const; // INADDR_ANY equivalent
-    bool IsIPv4() const;    // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0)
-    bool IsIPv6() const;    // IPv6 address (not mapped IPv4, not Tor)
+    [[nodiscard]] bool IsIPv4() const { return m_net == NET_IPV4; } // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0)
+    [[nodiscard]] bool IsIPv6() const { return m_net == NET_IPV6; } // IPv6 address (not mapped IPv4, not Tor)
     bool IsRFC1918() const; // IPv4 private networks (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12)
     bool IsRFC2544() const; // IPv4 inter-network communications (198.18.0.0/15)
     bool IsRFC6598() const; // IPv4 ISP-level NAT (100.64.0.0/10)
@@ -179,9 +179,9 @@ class CNetAddr
     bool IsRFC6052() const; // IPv6 well-known prefix for IPv4-embedded address (64:FF9B::/96)
     bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765)
     bool IsHeNet() const;   // IPv6 Hurricane Electric - https://he.net (2001:0470::/36)
-    bool IsTor() const;
-    bool IsI2P() const;
-    bool IsCJDNS() const;
+    [[nodiscard]] bool IsTor() const { return m_net == NET_ONION; }
+    [[nodiscard]] bool IsI2P() const { return m_net == NET_I2P; }
+    [[nodiscard]] bool IsCJDNS() const { return m_net == NET_CJDNS; }
     [[nodiscard]] bool HasCJDNSPrefix() const { return m_addr[0] == 0xfc; }
     bool IsLocal() const;
     bool IsRoutable() const;