Question

Why can you kind of cheat compiler this way:

const int a = 5;
*((int*)&a)=5;   // VC/armcc does not complain

when above is “abridged” equivalent of this:

const int *ptr2const = &a;
int *ptr = ptr2const;      // as expected error is raised here
*ptr = 5;

Answer 1

C-style casts allow you to cast away constness like in your example. In C++, you would normally use the new style casts such as static_cast<>, which don’t allow you to cast away constness. Only const_cast<> allows you to do that.