Pointers and References as member variables of const objects

Question

The following code compiles fine. However I wonder if it is legal C++. So more specific, if I have a const object, am I allowed to modify variables through pointers/referenc

Answer 1

I find the best way to think about const in C++ is that it protects the physical bits of the object. It has no real protection for objects that it refers to. You can control the object definition with const methods to provide deeper protection of values but by default C++ really only protects the physical object itself

One of the reasons why C++ allows you to modify the contents of a pointer through a const value is that it really can't stop you. Imagine for a second that C++ disallowed that particular construct. You could trivially violate it by doing the following

size_t t1 = (size_t)bar.a; // legal 
int* t2 = (int*)t1;        // legal 
*t2 = 3;                   // exactly the same as *bar.a = 3