Why std :: transform and similar increments for for for (void) loop?

Question

What is the purpose of (void) ++__result in the code below?

Implementation for std :: transform:

 // std::transform template <class _InputIterator, class _OutputIterator, class _UnaryOperation> inline _LIBCPP_INLINE_VISIBILITY _OutputIterator transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op) { for (; __first != __last; ++__first, (void) ++__result) *__result = __op(*__first); return __result; } 

Answer 1

You can overload operator, Casting or the void operand prohibits the call of any overloaded operator, since overloaded operators cannot accept void parameters.

Answer 2

It avoids calling the overloaded operator, , if any. Since the void type cannot be an argument to a function (operator).

Another approach would be to insert void() in the middle:

 ++__first, void(), ++__result