const-cast

This question already has an answer here: Two different values at the same memory address 6 answers Consider the following code: I declare a new reference end assign it to value a via const_cast. Then I just increase the reference value print the addresses and values. #include <iostream> using namespace std; int main() { const int a = 7; int &b = const_cast<int&>(a); ++b; cout<<"Addresses "<<&a<<" "<<&b<<endl; cout<<"Values "<<a<<" "<<b<<endl; } //output Addresses 0x7fff11f8e30c 0x7fff11f8e30c Values 7 8 How can i have 2 different values in the same address?? Modifying a constant object gives

With the following code void TestF(const double ** testv){;} void callTest(){ double** test; TestF(test); } I get this: 'TestF' : cannot convert parameter 1 from 'double **' to 'const double **' I cannot understand why. Why test cannot be silently casted to const double** ? Why should I do it explicitly? I know that TestF(const_cast<const double**>(test)) makes my code correct, but I feel this should be unnecessary. Are there some key concepts about const that I'm missing? AnT The language allows implicit conversion from double ** to const double *const * , but not to const double ** . The

I have a private variable in my Student class defined as: const int studentNumnber; I am trying to write a copy constructor for the Student and I need to cast away the constness to do this, unfortunately I don't understand how to use std::const_cast . This is what I am trying to do in my copy constructor: Student(const Student & s) : Person(p.getName(), p.getEmailAddress(), p.getBirthDate()), school(0), studentNumber(0) { school = new char[strlen(s.school) + 1]; strcpy_s(school, strlen(s.school) + 1, s.school); const_cast<int*>(this)->studentNumber = s.studentNumber; //studentNumber = s