c++ find 用法

#include 

    iterator find( iterator start, iterator end, const TYPE& val );

例一，在容器中查找：
   int num_to_find = 3;
 
   vector v1;
   for( int i = 0; i < 10; i++ ) {
     v1.push_back(i);
   }
 
   vector::iterator result;
   result = find( v1.begin(), v1.end(), num_to_find );
 
   if( result == v1.end() ) {
     cout << "Did not find any element matching " << num_to_find << endl;
   }
 
   else {
     cout << "Found a matching element: " << *result << endl;
   }