Iterator: merge several changes from trunk.

- Update iterator_facade test for #1019
  (header change already merged).
- Category of each iterator is reduced to a known category before we try to
  find a minimum. Fixes #1517.
- `function_input_iterator` from Dean Michael Berris. Fixes #2893
- Fix typo in `boost/iterator.hpp`. Fixes #3434.
- Always include `add_reference` header in iterator adaptor header.

Did not merge changes for #1427.


[SVN r70709]

test/function_input_iterator_test.cpp

@@ -0,0 +1,70 @@
+// Copyright 2010 (c) Dean Michael Berris
+// Distributed under the Boost Software License Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/iterator/function_input_iterator.hpp>
+#include <vector>
+#include <iterator>
+#include <cassert>
+#include <algorithm>
+#include <iostream>
+
+struct ones {
+    typedef int result_type;
+    result_type operator() () {
+        return 1;
+    }
+};
+
+int ones_function () {
+    return 1;
+}
+
+using namespace std;
+
+int main(int argc, char * argv[])
+{
+    // test the iterator with function objects
+    ones ones_generator;
+    vector<int> values(10);
+    generate(values.begin(), values.end(), ones());
+    
+    vector<int> generated;
+    copy(
+        boost::make_function_input_iterator(ones_generator, 0),
+        boost::make_function_input_iterator(ones_generator, 10),
+        back_inserter(generated)
+        );
+
+    assert(values.size() == generated.size());
+    assert(equal(values.begin(), values.end(), generated.begin()));
+    cout << "function iterator test with function objects successful." << endl;
+
+    // test the iterator with normal functions
+    vector<int>().swap(generated);
+    copy(
+        boost::make_function_input_iterator(&ones_function, 0),
+        boost::make_function_input_iterator(&ones_function, 10),
+        back_inserter(generated)
+        );
+
+    assert(values.size() == generated.size());
+    assert(equal(values.begin(), values.end(), generated.begin()));
+    cout << "function iterator test with pointer to function successful." << endl;
+
+    // test the iterator with a reference to a function
+    vector<int>().swap(generated);
+    copy(
+        boost::make_function_input_iterator(ones_function, 0),
+        boost::make_function_input_iterator(ones_function, 10),
+        back_inserter(generated)
+        );
+
+    assert(values.size() == generated.size());
+    assert(equal(values.begin(), values.end(), generated.begin()));
+    cout << "function iterator test with reference to function successful." << endl;
+
+    return 0;
+}
+