where is the problem vector find c++ ??

when i compile i has an error and i cannot understand where is the problem?

class Edge{  
public:  
      int nid;  
      bool operator==(const Edge& 开发者_运维问答edge) const {  
            return nid == edge.nid;  
      }  
 };  

and problem here

vector<Edge> edges;  
vector<Edge>::iterator it;  
it = find (edges.begin(), edges.end(), nid);

if( it != edges.end() )  
      edges.erase(it); 

any ideas ?!!!?

find will compare (with ==) the objects of type Edge in the vector with nid. I guess that nid is of type int and that won't work unless you implement operator== between Edge and int.

You can try :

it = find (edges.begin(), edges.end(), Edge(nid));

You haven't described the extract symptoms of your problem, but I guess that it is related to that didn't define the operator!=

You probably want to define it as

   bool operator!=(const Edge&edge)const {
      return !(*this == edge);
   }

also if your find(...,nid) is taking nid as an integer argument, you probably also need to overload the == operator as

   bool operator==(const int&edge)const {
      return this->nid == edge;
   }

You can either overload the operator!=, too, or simply negate the if condition.

Assuming nid is the same type as in the class I assume you get a complaint about the type of the third argument to find(). I think you can switch it to:

vector<Edge>::iterator it = find (edges.begin(), edges.end(), edges.begin() + nid);