const 真难啊

const 真TM 难啊

const int a = 3; // easy const int *b = &a; const int *x = b; // *x is a const value   *x = 4; // error const int *c = &a; x = c; // right const int* const y = b; // y is const pointer, and *y is const value *y = 4; // error

 y = c // error

list<int>::const_reverse_iterator it;// the it can be change, for example: it++; but *it can not be changed

template <class T>

void print(const T * para)

{

typename T::const_iterator it;// here, we must use const_iterator, for the element value in para can't be changed

}

const vector<int> nums;

vector<int>::const_iterator it = nums.begin(); // nums value is const , so we must use const_iterator