C + + in the const and iterator (iterator) use of the detailed

An iterator (iterator) is a pointer type, and also points to the Const pointer itself (address) and the value indicated by the const pointer, in two cases;

But the writing and const built-in pointers are different;

char * const is equivalent to const container<>::iterator; You can modify the value that the pointer refers to, but you cannot modify the pointer's address;

const char * equivalent to container<>::const_iterator; You can modify the pointer address, but you cannot modify the value indicated by the pointer;

Note The code example, two const and iterators;

Code:

* * * * effectivecpp.cpp * *  Created on:2013.11.13 *      author:caroline
      
* */*eclipse CDT; GCC 4.7.1*/
      
#include <iostream>  
#include <vector>  
      
int main (void) {  
      
    std::vector< Int> IV = {1, 2, 3, 4, 5};  
    Const AUTO IT = Iv.begin (); The const iterator is equivalent to t* const, and the pointer itself (address) is fixed;  
    Std::cout << "*it =" << *it << Std::endl;  
    ++it; Error  
    *it = ten;  
    Std::cout << "*it =" << *it << Std::endl;  
      
     IV = {1, 2, 3, 4, 5};  
     Auto CIT = Iv.cbegin (); Cbegin, equivalent to Const_iterator, the finger of the pointer is fixed;  
     Std::vector<int>::const_iterator cit = Iv.begin ();  
     Std::cout << "*cit =" << *cit << Std::endl;  
     ++cit;  
     *cit = 10; Error  
     std::cout << "*cit =" << *cit << Std::endl;  
      
    return 0;  
      
}

Author: csdn Blog spike_king

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