C++ std::for_each

// std::for_eachtemplate <class InputIterator, class Function>   Function for_each (InputIterator first, InputIterator last, Function fn);

template<class InputIterator, class Function>  Function for_each(InputIterator first, InputIterator last, Function fn){  while (first!=last) {    fn (*first);    ++first;  }  return fn;      // or, since C++11: return move(fn);}

GCC4.7 中 for_each

  /**   *  @brief Apply a function to every element of a sequence.   *  @ingroup non_mutating_algorithms   *  @param  __first  An input iterator.   *  @param  __last   An input iterator.   *  @param  __f      A unary function object.   *  @return   @p __f (std::move(@p __f) in C++0x).   *   *  Applies the function object @p __f to each element in the range   *  @p [first,last).  @p __f must not modify the order of the sequence.   *  If @p __f has a return value it is ignored.  */  template<typename _InputIterator, typename _Function>    _Function    for_each(_InputIterator __first, _InputIterator __last, _Function __f)    {      // concept requirements      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)      __glibcxx_requires_valid_range(__first, __last);      for (; __first != __last; ++__first)__f(*__first);      return _GLIBCXX_MOVE(__f);    }