Why can't you just re-bind the constant? So instead of
const int w = 10;
int* wp = const_cast (&w);
*wp = 20;
// some code
just introduce the different constant with the same name
const int w = 10;
{
const int w = 20;
// the same code
}
If the "new" constant should depend on its own value, you should introduce another constant (const int _w = w; const int w = _w * 2;). The unnecessary assignments will be optimized out by compiler--because we've seen it has done such optimisation, as it's the reason why you asked your question.
