[Boost-bugs] [Boost C++ Libraries] #2893: Function Input Iterator

Subject: [Boost-bugs] [Boost C++ Libraries] #2893: Function Input Iterator
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-03-27 11:13:28

#2893: Function Input Iterator
-------------------------------------+--------------------------------------
 Reporter:  anonymous                |       Owner:  dave          
     Type:  Library Submissions      |      Status:  new           
Milestone:  To Be Determined         |   Component:  iterator      
  Version:                           |    Severity:  Not Applicable
 Keywords:  iterator function input  |  
-------------------------------------+--------------------------------------
 Simply put a the function input iterator implementation wraps a nullary
 function object and allows for bounded iterators using an embedded state
 variable. The use case is for something like the following:

 {{{
 struct generator {
  typedef int result_type;
  generator() { srand(time(0)); }
  result_type operator() () const { return rand(); }
 };

 using namespace std;
 using namespace boost;

 int main(int argc, char * argv[]) {
  generator f;
  copy(
    make_function_input_iterator(f, infinite()),
    make_function_input_iterator(f, infinite()),
    ostream_iterator<int>(cout, " ")
    );
  return 0;
 }
 }}}

 And if you don't want an infinite range, you can simply bound it:

 {{{
 copy(
   make_function_input_iterator(f, 0),
   make_function_input_iterator(f, 10),
   ostream_iterator<int>(cout, " ")
 );
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2893>
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