Proposed resolution:

This wording is relative to N4928.

1. Modify [specialized.algorithms.general], General, as indicated:

   -4- Some algorithms specified in [specialized.algorithms] make use of the exposition-only function voidify:

   
   template<class T>
     constexpr void* voidify(T& obj) noexcept {
       return const_cast<void*>(static_cast<const volatile void*>(addressof(obj)));
     }