new file, part of the iterator adaptors library

[SVN r9350]

include/boost/function_output_iterator.hpp

@@ -0,0 +1,55 @@
+// (C) Copyright Jeremy Siek 2001. Permission to copy, use, modify,
+// sell and distribute this software is granted provided this
+// copyright notice appears in all copies. This software is provided
+// "as is" without express or implied warranty, and with no claim as
+// to its suitability for any purpose.
+
+// Revision History:
+
+// 27 Feb 2001   Jeremy Siek
+//      Initial checkin.
+
+#ifndef BOOST_FUNCTION_OUTPUT_ITERATOR_HPP
+#define BOOST_FUNCTION_OUTPUT_ITERATOR_HPP
+
+#include <iterator>
+
+namespace boost {
+
+  template <class UnaryFunction>
+  class function_output_iterator {
+    typedef function_output_iterator self;
+  public:
+    typedef std::output_iterator_tag iterator_category;
+    typedef void                value_type;
+    typedef void                difference_type;
+    typedef void                pointer;
+    typedef void                reference;
+
+    explicit function_output_iterator(const UnaryFunction& f = UnaryFunction())
+      : m_f(f) {}
+
+    struct output_proxy {
+      output_proxy(UnaryFunction& f) : m_f(f) { }
+      template <class T> output_proxy& operator=(const T& value) {
+        m_f(value); 
+        return *this; 
+      }
+      UnaryFunction& m_f;
+    };
+    output_proxy operator*() { return output_proxy(m_f); }
+    self& operator++() { return *this; } 
+    self& operator++(int) { return *this; }
+  private:
+    UnaryFunction m_f;
+  };
+
+  template <class UnaryFunction>
+  inline function_output_iterator<UnaryFunction>
+  make_function_output_iterator(const UnaryFunction& f = UnaryFunction()) {
+    return function_output_iterator<UnaryFunction>(f);
+  }
+
+} // namespace boost
+
+#endif // BOOST_FUNCTION_OUTPUT_ITERATOR_HPP