Merge pull request #1664 from YehezkelShB/FixPostIncrementOfCountedIt…

…erator

Fix post increment of counted iterator

include/range/v3/iterator/counted_iterator.hpp

@@ -85,6 +85,7 @@ namespace ranges
         {
             CPP_assert(std::is_void<decltype(current_++)>());
             ++current_;
+            --cnt_;
         }
         constexpr auto post_increment_(std::false_type) -> decltype(current_++)
         {

test/iterator/CMakeLists.txt

@@ -6,3 +6,4 @@ rv3_add_test(test.iter.iterator iter.iterator iterator.cpp)
 rv3_add_test(test.iter.common_iterator iter.common_iterator common_iterator.cpp)
 rv3_add_test(test.iter.reverse_iterator iter.reverse_iterator reverse_iterator.cpp)
 rv3_add_test(test.iter.unformatted_ostream_iterator iter.unformatted_ostream_iterator unformatted_ostream_iterator.cpp)
+rv3_add_test(test.iter.counted_iterator iter.counted_iterator counted_iterator.cpp)

test/iterator/counted_iterator.cpp

@@ -0,0 +1,40 @@
+// Range v3 library
+//
+//  Copyright Eric Niebler 2014-present
+//
+//  Use, modification and distribution is subject to 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)
+//
+// Project home: https://github.com/ericniebler/range-v3
+
+#include <range/v3/iterator/counted_iterator.hpp>
+
+#include "../simple_test.hpp"
+
+// iterator that models input_iterator (has void-returning postfix increment operator)
+struct Iterator
+{
+    using value_type = int;
+    using difference_type = int;
+
+    int counter = 0;
+
+    int operator*() const { return counter; }
+    Iterator& operator++() { ++counter; return *this; }
+    void operator++(int) { ++counter; }
+    bool operator==(const Iterator& rhs) const { return counter == rhs.counter; }
+    bool operator!=(const Iterator& rhs) const { return !(*this == rhs); }
+};
+
+int main()
+{
+    CPP_assert(ranges::input_iterator<Iterator>);
+    auto cnt = ranges::counted_iterator<Iterator>(Iterator(), 1);
+    CHECK(*cnt == 0);
+    cnt++;
+    CHECK(cnt == ranges::default_sentinel);
+
+    return test_result();
+}