Added new DNS::Resolve static method and organized it per OS.

src/io/socket/TCP_W32.cpp

@@ -347,6 +347,55 @@ namespace ehs
 		return (bool)r;
 	}
 
+	void TCP::SetIPv6Only(const bool value)
+	{
+		if (addrType != AddrType::IPV6)
+		{
+			EHS_LOG_INT(LogType::WARN, 0, "Cannot set IPv6 only mode while socket is not using IPv6.");
+			return;
+		}
+
+		if (!IsValid())
+		{
+			EHS_LOG_INT(LogType::WARN, 1, "Attempted to set IPv6 only mode while socket is not initialized.");
+			return;
+		}
+
+		const int result = (int)value;
+		if (setsockopt(hdl, IPPROTO_IPV6, IPV6_V6ONLY, &result, sizeof(int)) == -1)
+		{
+			EHS_LOG_INT(LogType::ERR, 2, "Failed to set IPv6 only mode with error #" + Str_8::FromNum(errno) + ".");
+			return;
+		}
+
+		EHS_LOG_SUCCESS();
+	}
+
+	bool TCP::IsIPv6Only() const
+	{
+		if (addrType != AddrType::IPV6)
+			return false;
+
+		if (!IsValid())
+		{
+			EHS_LOG_INT(LogType::WARN, 1, "Attempted to set IPv6 only mode while socket is not initialized.");
+			return false;
+		}
+
+		int result;
+		socklen_t len = sizeof(int);
+
+		if (getsockopt(hdl, IPPROTO_IPV6, IPV6_V6ONLY, &result, &len) == -1)
+		{
+			EHS_LOG_INT(LogType::ERR, 2, "Failed to set IPv6 only mode with error #" + Str_8::FromNum(errno) + ".");
+			return false;
+		}
+
+		EHS_LOG_SUCCESS();
+
+		return result;
+	}
+
 	bool TCP::IsValid() const
 	{
 		return hdl != EHS_INVALID_SOCKET;