/* Code for exercise 19.2. |  | "C++ Solutions--Companion to The C++ Programming Language, Third Edition" | by David Vandevoorde; Addison-Wesley 1998; ISBN 0-201-30965-3. | | Permission to use, copy, modify, distribute and sell this software | and its documentation for any purpose is hereby granted without fee. | The author makes no representations about the suitability of this | software for any purpose.  It is provided "as is" without express or | implied warranty. `----------------------------------------------------------------------*/#include <algorithm>#include <functional>#include <iterator>#include <stdio.h>struct Sink : std::iterator<std::output_iterator_tag, void, void, void, void> {   template<typename T> Sink& operator=(T const&) { return *this; }   Sink& operator*() { return *this; }   Sink const& operator*() const { return *this; }   Sink& operator++() { return *this; } // Pre-increment   Sink& operator++(int) { return *this; } // Post-increment};namespace mystd {   template<typename In, typename F> inline   F for_each(In begin, In end, F f) {      std::transform(begin, end, Sink(), f);      return f;   } }int primes[] = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 };struct Print: std::unary_function<int, int> {   int operator()(int i) const {      printf("%d\n", i);      return i;   }};int main() {   mystd::for_each(&primes[0], &primes[0]+sizeof(primes)/sizeof(primes[0]),                   Print());   return 0;}