erase后程序执行报错，是否是由于迭代器失效，如何修改？?报错

#include <string>
#include <list>
#include <iostream>
using namespace std;
void eraseStr(list<string>& slist,string str)
{ for(list<string>::iterator iter=slist.begin();iter!=slist.en();++iter)     {  
    if(*iter == str)
     {  iter = slist.erase(iter);
        --iter;   
     }
    }
}
int main()
{  
    string str;  
    list<string> slist;  
    while(cin>>str)  
        slist.push_back(str);  
    eraseStr(slist,"a");//假设上面输入存在a
}