On Friday, 13 July 2018 at 13:52:27 UTC, Timoses wrote:
I suppose this is another good example of how casting can be
dangerous?
E.g. also:
immutable int i = 3;
int* j = cast(int*)&i;
assert(i == 3);
*j = 4;
assert(j == &i); // data occupies same address space
assert(i == 3 && *j == 4); // yet the values differ
No, casting classes to their subclasses is not dangerous to
program integrity, because it is checked. It is just a regular
bug that terminates the program when encountered.
But casting away immutable can break program integrity as your
example demonstrates. For that reason the compiler won't let you
do that if you wrap that code in @safe, unlike the class cast.
