我该如何解决C ++中的不完整类型错误？

Question

我正在使用omnetpp v4.6的INET Framework 3.2.2。 我的代码正在从INET框架导入.h文件，但是即使我在代码引用中添加了INET框架并且我已经在#include中写入了完整的路径目录，并且向前声明了我需要的类，但它仍然无法识别我正在使用的属性，并给我“不完整的类型”错误，但它们在内联布尔运算符中被很好地识别，没有错误。 这是代码：

#ifndef OPENFLOW_H_
#define OPENFLOW_H_

#define OFP_VERSION   0x01

#include "inet/common/INETDefs.h"

//doesn't recognize the includes
#include <inet/networklayer/contract/ipv4/IPv4Address.h>
#include <inet/linklayer/common/MACAddress.h> 

class MACAddress; 
class IPv4Address;


struct oxm_basic_match {
    int OFB_IN_PORT;
    MACAddress OFB_ETH_DST; //error (field 'OFB_ETH_DST' has incomplete type 'MACAddress')
    MACAddress OFB_ETH_SRC; //error (field 'OFB_ETH_SRC' has incomplete type 'MACAddress')
    int OFB_ETH_TYPE;
    IPv4Address OFB_IPV4_DST; //error (field 'OFB_IPV4_DST' has incomplete type 'IPv4Address')
    int OFB_ARP_OP; /* ARP opcode. */ 
    IPv4Address OFB_ARP_SPA; /* ARP source IPv4 address. */ //error (field 'OFB_ARP_SPA' has incomplete type 'IPv4Address')
    IPv4Address OFB_ARP_TPA; /* ARP target IPv4 address. */ //error (field 'OFB_ARP_TPA' has incomplete type 'IPv4Address')
    MACAddress OFB_ARP_SHA; /* ARP source hardware address. */ //error (field 'OFB_ARP_SHA' has incomplete type 'MACAddress')
    MACAddress OFB_ARP_THA; /* ARP target hardware address. */ //error (field 'OFB_ARP_THA' has incomplete type 'MACAddress')
    uint32_t wildcards;
    int getPriority();
};


inline bool operator==(const oxm_basic_match &m1, const oxm_basic_match& m2) {
    return m2.OFB_IN_PORT == m1.OFB_IN_PORT
            && m2.OFB_ETH_DST == m1.OFB_ETH_DST
            && m2.OFB_ETH_SRC == m1.OFB_ETH_SRC
            && m2.OFB_ETH_TYPE == m1.OFB_ETH_TYPE
            && m2.OFB_ARP_OP == m1.OFB_ARP_OP
            && m2.OFB_ARP_SHA == m1.OFB_ARP_SHA
            && m2.OFB_ARP_SPA == m1.OFB_ARP_SPA
            && m2.OFB_ARP_THA == m1.OFB_ARP_THA
            && m2.OFB_ARP_TPA == m1.OFB_ARP_TPA;
}

请帮忙吗？

Answer 1

在这种情况下，您不能使用前向声明。 您应该包括包含完整类定义的头文件。 类MACAddress {...}

前向声明只能用于指针或引用。 这是一个更完整的答案- 什么时候可以使用前向声明？