关于STL容器删除元素的模板方法

template<class T,class Function>
void EraseFromBy(T& from,Function by)
{
T::iterator iter = from.begin() , prev = iter;
while(iter!=from.end())
{
  if(by(*iter))
  {
   t.erase(iter);
   if(prev == iter)
    iter = prev = from.begin();
   else
   {
    iter = prev;
    iter++;
   }
  }
  else
  {
   prev = iter;
   iter++;
  }
}
}

使用方法:
bool ShouldBeDeal(int a)    //该函数传递给EraseFromBy,用于做删除的判断选项
{
if(a%2==0)
  return true;
return false;
}
void main( void )
{
set<int> s;
s.insert(1);
s.insert(2);
s.insert(3);
s.insert(4);
copy(s.begin(),s.end(),ostream_iterator<int>(cout,\"\n\"));
EraseFromBy(s,ShouldBeDeal);
copy(s.begin(),s.end(),ostream_iterator<int>(cout,\"\n\"));
}