reinterpret_cast casts away qualifiers

Question

I add an issue on reinterpreting a variable and I don\'t know why..

int ProgressBar(const uint64_t data_sent, const uint64         


        

Answer 1

You need to also use a const_cast to remove const qualifiers. Also, casting from void * can use static_cast, it does not need to reinterpret. For example:

Dialog const *dialog = static_cast
(data);
Dialog *d2 = const_cast
(dialog);

However , make sure that the Dialog is actually not a const object; attempting to modify a const object (presumably setValue does this) causes undefined behaviour.

I'd suggest rethinking the interface to ProgressBar to avoid needing this cast.