If you do Assert(ExpensiveOp()), removing all of it is only a valid optimization if ExpensiveOp() is 100% side-effect free. But even when that is the case, the

If you do Assert(ExpensiveOp()), removing all of it is only a valid optimization if ExpensiveOp() is 100% side-effect free. But even when that is the case, the compiler won't inline ExpensiveOp() and go through the effort of proving that it's side effect free if it's sufficiently complex.