使用vector::iterator进行重复值查询，结果一直编译错误？？？

#include <iostream>
#include <vector>
#include <iterator>
using namespace std;
class solution
{
public:
bool containDuplicate(vector<int>&nums)
{
vector<int>::iterator eFirst=nums.begin();
vector<int>::iterator eLast=nums.end();
vector<int>::iterator eBegin;
vector<int>::iterator eEnd;
for(eBegin=eFirst;eBegin!=eLast;eBegin++){
for(eEnd=eBegin++;eEnd!=eLast;eEnd++)
if(*eBegin!=*eEnd)
return false;
eBegin--;
}
return true;
}
};
int main()
{
vector<int>eVector(20);
solution s;
s.containDuplicate(eVector);
system("pause");
}