[C/C++]map自定义比较函数

//自定义map的key
typedef struct UrlKey
{
	uint64_t dwBussID;
	uint64_t dwVersion;
	uint64_t dwHashUrl;
}UrlKey;

//自定义map的value
typedef struct UrlValue
{
	string strUrl;
}UrlValue;

//map的比较函数
struct cmp_key
{
	bool operator()(const UrlKey &k1, const UrlKey &k2)const
	{
		if(k1.dwBussID != k2.dwBussID)
		{
			return k1.dwBussID < k2.dwBussID;
		}

		if(k1.dwVersion != k2.dwVersion)
		{
			return k1.dwVersion < k2.dwVersion;
		}
		if(k1.dwHashUrl != k2.dwHashUrl)
		{
			return k1.dwHashUrl < k2.dwHashUrl;
		}
　　　　　　　　  return false;
	}
};


int main()
{
　　map<UrlKey, UrlValue, cmp_key> UrlMap;
　　UrlKey stKey;
　　stKey.dwBussID = 1;
　　stKey.dwVersion = 2;
　　stKey.dwHashUrl = 3;
        
　　UrlValue stValue;
　　stValue.strUrl = "abc";

　　UrlMap[stKey] = stValue;

　　return 0;
}