Merge pull request #305 from Crzyrndm/dev-iterator-improvements-2

Remove uses of std::iterator (deprecated in C++17) + improvements

include/xlnt/workbook/worksheet_iterator.hpp

@@ -37,18 +37,22 @@ class worksheet;
 // because one needs to point at a const workbook and the other needs
 // to point at a non-const workbook stored as a member variable, respectively.
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using ws_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    worksheet, std::ptrdiff_t, worksheet *, worksheet>;
 
 /// <summary>
 /// An iterator which is used to iterate over the worksheets in a workbook.
 /// </summary>
-class XLNT_API worksheet_iterator : public ws_iter_type
+class XLNT_API worksheet_iterator
 {
 public:
+    /// <summary>
+    /// iterator tags required for use with standard algorithms and adapters
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = worksheet;
+    using difference_type = std::ptrdiff_t;
+    using pointer = worksheet *;
+    using reference = worksheet; // intentionally value
+
     /// <summary>
     /// Constructs a worksheet iterator from a workbook and sheet index.
     /// </summary>
@@ -57,19 +61,41 @@ public:
     /// <summary>
     /// Copy constructs a worksheet iterator from another iterator.
     /// </summary>
-    worksheet_iterator(const worksheet_iterator &);
+    worksheet_iterator(const worksheet_iterator &) = default;
 
     /// <summary>
-    /// Assigns the iterator so that it points to the same worksheet in the same workbook.
+    /// Copy assigns the iterator so that it points to the same worksheet in the same workbook.
     /// </summary>
-    worksheet_iterator &operator=(const worksheet_iterator &);
+    worksheet_iterator &operator=(const worksheet_iterator &) = default;
+
+    /// <summary>
+    /// Move constructs a worksheet iterator from a temporary iterator.
+    /// </summary>
+    worksheet_iterator(worksheet_iterator &&) = default;
+
+    /// <summary>
+    /// Move assign the iterator from a temporary iterator
+    /// </summary>
+    worksheet_iterator &operator=(worksheet_iterator &&) = default;
+
+    /// <summary>
+    /// Default destructor
+    /// </summary>
+    ~worksheet_iterator() = default;
 
     /// <summary>
     /// Dereferences the iterator to return the worksheet it is pointing to.
     /// If the iterator points to one-past-the-end of the workbook, an invalid_parameter
     /// exception will be thrown.
     /// </summary>
-    worksheet operator*();
+    reference operator*();
+
+    /// <summary>
+    /// Dereferences the iterator to return the worksheet it is pointing to.
+    /// If the iterator points to one-past-the-end of the workbook, an invalid_parameter
+    /// exception will be thrown.
+    /// </summary>
+    const reference operator*() const;
 
     /// <summary>
     /// Returns true if this iterator points to the same worksheet as comparand.
@@ -93,11 +119,23 @@ public:
     /// </summary>
     worksheet_iterator &operator++();
 
+    /// <summary>
+    /// Post-decrement the iterator's internal workseet index. Returns a copy of the
+    /// iterator as it was before being incremented.
+    /// </summary>
+    worksheet_iterator operator--(int);
+
+    /// <summary>
+    /// Pre-decrement the iterator's internal workseet index. Returns a refernce
+    /// to the same iterator.
+    /// </summary>
+    worksheet_iterator &operator--();
+
 private:
     /// <summary>
     /// The target workbook of this iterator.
     /// </summary>
-    workbook &wb_;
+    workbook *wb_;
 
     /// <summary>
     /// The index of the worksheet in wb_ this iterator is currently pointing to.
@@ -106,18 +144,21 @@ private:
 };
 
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using c_ws_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    const worksheet, std::ptrdiff_t, const worksheet *, const worksheet>;
-
 /// <summary>
 /// An iterator which is used to iterate over the worksheets in a const workbook.
 /// </summary>
-class XLNT_API const_worksheet_iterator : public c_ws_iter_type
+class XLNT_API const_worksheet_iterator
 {
 public:
+    /// <summary>
+    /// iterator tags required for use with standard algorithms and adapters
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = const worksheet;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const worksheet *;
+    using reference = const worksheet; // intentionally value
+
     /// <summary>
     /// Constructs a worksheet iterator from a workbook and sheet index.
     /// </summary>
@@ -126,19 +167,34 @@ public:
     /// <summary>
     /// Copy constructs a worksheet iterator from another iterator.
     /// </summary>
-    const_worksheet_iterator(const const_worksheet_iterator &);
+    const_worksheet_iterator(const const_worksheet_iterator &) = default;
 
     /// <summary>
-    /// Assigns the iterator so that it points to the same worksheet in the same workbook.
+    /// Copy assigns the iterator so that it points to the same worksheet in the same workbook.
     /// </summary>
-    const_worksheet_iterator &operator=(const const_worksheet_iterator &);
+    const_worksheet_iterator &operator=(const const_worksheet_iterator &) = default;
+
+    /// <summary>
+    /// Move constructs a worksheet iterator from a temporary iterator.
+    /// </summary>
+    const_worksheet_iterator(const_worksheet_iterator &&) = default;
+
+    /// <summary>
+    /// Move assigns the iterator from a temporary iterator
+    /// </summary>
+    const_worksheet_iterator &operator=(const_worksheet_iterator &&) = default;
+
+    /// <summary>
+    /// Default destructor
+    /// </summary>
+    ~const_worksheet_iterator() = default;
 
     /// <summary>
     /// Dereferences the iterator to return the worksheet it is pointing to.
     /// If the iterator points to one-past-the-end of the workbook, an invalid_parameter
     /// exception will be thrown.
     /// </summary>
-    const worksheet operator*();
+    const reference operator*() const;
 
     /// <summary>
     /// Returns true if this iterator points to the same worksheet as comparand.
@@ -162,11 +218,23 @@ public:
     /// </summary>
     const_worksheet_iterator &operator++();
 
+    /// <summary>
+    /// Post-decrement the iterator's internal workseet index. Returns a copy of the
+    /// iterator as it was before being incremented.
+    /// </summary>
+    const_worksheet_iterator operator--(int);
+
+    /// <summary>
+    /// Pre-decrement the iterator's internal workseet index. Returns a refernce
+    /// to the same iterator.
+    /// </summary>
+    const_worksheet_iterator &operator--();
+
 private:
     /// <summary>
     /// The target workbook of this iterator.
     /// </summary>
-    const workbook &wb_;
+    const workbook *wb_;
 
     /// <summary>
     /// The index of the worksheet in wb_ this iterator is currently pointing to.

include/xlnt/worksheet/cell_iterator.hpp

@@ -40,18 +40,21 @@ class cell;
 class cell_reference;
 class range_reference;
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using c_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    cell, std::ptrdiff_t, cell *, cell>;
-
 /// <summary>
 /// A cell iterator iterates over a 1D range by row or by column.
 /// </summary>
-class XLNT_API cell_iterator : public c_iter_type
+class XLNT_API cell_iterator
 {
 public:
+    /// <summary>
+    /// iterator tags required for use with standard algorithms and adapters
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = cell;
+    using difference_type = std::ptrdiff_t;
+    using pointer = cell *;
+    using reference = cell; // intentionally value
+
     /// <summary>
     /// Constructs a cell_iterator from a worksheet, range, and iteration settings.
     /// </summary>
@@ -61,17 +64,38 @@ public:
     /// <summary>
     /// Constructs a cell_iterator as a copy of an existing cell_iterator.
     /// </summary>
-    cell_iterator(const cell_iterator &other);
+    cell_iterator(const cell_iterator &) = default;
 
     /// <summary>
     /// Assigns this iterator to match the data in rhs.
     /// </summary>
-    cell_iterator &operator=(const cell_iterator &rhs) = default;
+    cell_iterator &operator=(const cell_iterator &) = default;
+
+    /// <summary>
+    /// Constructs a cell_iterator by moving from a cell_iterator temporary
+    /// </summary>
+    cell_iterator(cell_iterator &&) = default;
+
+    /// <summary>
+    /// Assigns this iterator to from a cell_iterator temporary
+    /// </summary>
+    cell_iterator &operator=(cell_iterator &&) = default;
+
+    /// <summary>
+    /// destructor for const_cell_iterator
+    /// </summary>
+    ~cell_iterator() = default;
 
     /// <summary>
     /// Dereferences this iterator to return the cell it points to.
     /// </summary>
-    cell operator*();
+    reference operator*();
+
+    /// <summary>
+    /// Dereferences this iterator to return the cell it points to.
+    /// </summary>
+    const reference operator*() const;
+
 
     /// <summary>
     /// Returns true if this iterator is equivalent to other.
@@ -135,7 +159,7 @@ private:
     /// If true, cells that don't exist in the worksheet will be skipped during iteration.
     /// </summary>
     bool skip_null_;
-    
+
     /// <summary>
     /// If true, when on the last column, the cursor will continue to the next row
     /// (and vice versa when iterating in column-major order) until reaching the
@@ -144,18 +168,21 @@ private:
     bool wrap_;
 };
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using cc_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    const cell, std::ptrdiff_t, const cell *, const cell>;
-
 /// <summary>
 /// A cell iterator iterates over a 1D range by row or by column.
 /// </summary>
-class XLNT_API const_cell_iterator : public cc_iter_type
+class XLNT_API const_cell_iterator
 {
 public:
+    /// <summary>
+    /// iterator tags required for use with standard algorithms and adapters
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = const cell;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const cell *;
+    using reference = const cell; // intentionally value
+
     /// <summary>
     /// Constructs a cell_iterator from a worksheet, range, and iteration settings.
     /// </summary>
@@ -163,19 +190,34 @@ public:
         const range_reference &limits, major_order order, bool skip_null, bool wrap);
 
     /// <summary>
-    /// Constructs a cell_iterator as a copy of an existing cell_iterator.
+    /// Constructs a const_cell_iterator as a copy of an existing cell_iterator.
     /// </summary>
-    const_cell_iterator(const const_cell_iterator &other);
+    const_cell_iterator(const const_cell_iterator &) = default;
 
     /// <summary>
     /// Assigns this iterator to match the data in rhs.
     /// </summary>
     const_cell_iterator &operator=(const const_cell_iterator &) = default;
 
+    /// <summary>
+    /// Constructs a const_cell_iterator by moving from a const_cell_iterator temporary
+    /// </summary>
+    const_cell_iterator(const_cell_iterator &&) = default;
+
+    /// <summary>
+    /// Assigns this iterator to from a const_cell_iterator temporary
+    /// </summary>
+    const_cell_iterator &operator=(const_cell_iterator &&) = default;
+
+    /// <summary>
+    /// destructor for const_cell_iterator
+    /// </summary>
+    ~const_cell_iterator() = default;
+
     /// <summary>
     /// Dereferences this iterator to return the cell it points to.
     /// </summary>
-    const cell operator*() const;
+    const reference operator*() const;
 
     /// <summary>
     /// Returns true if this iterator is equivalent to other.

include/xlnt/worksheet/range_iterator.hpp

@@ -35,19 +35,22 @@ namespace xlnt {
 
 class cell_vector;
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using r_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    cell_vector, std::ptrdiff_t, cell_vector *, cell_vector>;
-
 /// <summary>
 /// An iterator used by worksheet and range for traversing
 /// a 2D grid of cells by row/column then across that row/column.
 /// </summary>
-class XLNT_API range_iterator : public r_iter_type
+class XLNT_API range_iterator
 {
 public:
+    /// <summary>
+    /// iterator tags required for use with standard algorithms and adapters
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = cell_vector;
+    using difference_type = std::ptrdiff_t;
+    using pointer = cell_vector *;
+    using reference = cell_vector; // intentionally value
+
     /// <summary>
     /// Constructs a range iterator on a worksheet, cell pointing to the current
     /// row or column, range bounds, an order, and whether or not to skip null column/rows.
@@ -56,20 +59,40 @@ public:
         const range_reference &bounds, major_order order, bool skip_null);
 
     /// <summary>
-    /// Copy constructor.
+    /// Default copy constructor.
     /// </summary>
-    range_iterator(const range_iterator &other);
-
-    /// <summary>
-    /// Dereference the iterator to return a column or row.
-    /// </summary>
-    cell_vector operator*() const;
+    range_iterator(const range_iterator &) = default;
 
     /// <summary>
     /// Default assignment operator.
     /// </summary>
     range_iterator &operator=(const range_iterator &) = default;
 
+    /// <summary>
+    /// Default move constructor.
+    /// </summary>
+    range_iterator(range_iterator &&) = default;
+
+    /// <summary>
+    /// Default move assignment operator.
+    /// </summary>
+    range_iterator &operator=(range_iterator &&) = default;
+
+    /// <summary>
+    /// Default destructor
+    /// </summary>
+    ~range_iterator() = default;
+
+    /// <summary>
+    /// Dereference the iterator to return a column or row.
+    /// </summary>
+    reference operator*();
+
+    /// <summary>
+    /// Dereference the iterator to return a column or row.
+    /// </summary>
+    const reference operator*() const;
+
     /// <summary>
     /// Returns true if this iterator is equivalent to other.
     /// </summary>
@@ -127,19 +150,22 @@ private:
     bool skip_null_;
 };
 
-/// <summary>
-/// Alias the parent class of this iterator to increase clarity.
-/// </summary>
-using cr_iter_type = std::iterator<std::bidirectional_iterator_tag,
-    const cell_vector, std::ptrdiff_t, const cell_vector *, const cell_vector>;
-
 /// <summary>
 /// A const version of range_iterator which does not allow modification
 /// to the dereferenced cell_vector.
 /// </summary>
-class XLNT_API const_range_iterator : public cr_iter_type
+class XLNT_API const_range_iterator
 {
 public:
+    /// <summary>
+    /// this iterator meets the interface requirements of bidirection_iterator
+    /// </summary>
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = const cell_vector;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const cell_vector *;
+    using reference = const cell_vector; // intentionally value
+
     /// <summary>
     /// Constructs a range iterator on a worksheet, cell pointing to the current
     /// row or column, range bounds, an order, and whether or not to skip null column/rows.
@@ -148,20 +174,35 @@ public:
         const range_reference &bounds, major_order order, bool skip_null);
 
     /// <summary>
-    /// Copy constructor.
+    /// Default copy constructor.
     /// </summary>
-    const_range_iterator(const const_range_iterator &other);
-
-    /// <summary>
-    /// Dereferennce the iterator to return the current column/row.
-    /// </summary>
-    const cell_vector operator*() const;
+    const_range_iterator(const const_range_iterator &) = default;
 
     /// <summary>
     /// Default assignment operator.
     /// </summary>
     const_range_iterator &operator=(const const_range_iterator &) = default;
 
+    /// <summary>
+    /// Default move constructor.
+    /// </summary>
+    const_range_iterator(const_range_iterator &&) = default;
+
+    /// <summary>
+    /// Default move assignment operator.
+    /// </summary>
+    const_range_iterator &operator=(const_range_iterator &&) = default;
+
+    /// <summary>
+    /// Default destructor
+    /// </summary>
+    ~const_range_iterator() = default;
+
+    /// <summary>
+    /// Dereferennce the iterator to return the current column/row.
+    /// </summary>
+    const reference operator*() const;
+
     /// <summary>
     /// Returns true if this iterator is equivalent to other.
     /// </summary>

source/workbook/worksheet_iterator.cpp

@@ -28,18 +28,18 @@
 namespace xlnt {
 
 worksheet_iterator::worksheet_iterator(workbook &wb, std::size_t index)
-    : wb_(wb), index_(index)
+    : wb_(&wb), index_(index)
 {
 }
 
-worksheet_iterator::worksheet_iterator(const worksheet_iterator &rhs)
-    : wb_(rhs.wb_), index_(rhs.index_)
+worksheet_iterator::reference worksheet_iterator::operator*()
 {
+    return (*wb_)[index_];
 }
 
-worksheet worksheet_iterator::operator*()
+const worksheet_iterator::reference worksheet_iterator::operator*() const
 {
-    return wb_[index_];
+    return (*wb_)[index_];
 }
 
 worksheet_iterator &worksheet_iterator::operator++()
@@ -50,11 +50,24 @@ worksheet_iterator &worksheet_iterator::operator++()
 
 worksheet_iterator worksheet_iterator::operator++(int)
 {
-    worksheet_iterator old(wb_, index_);
+    worksheet_iterator old(*wb_, index_);
     ++*this;
     return old;
 }
 
+worksheet_iterator &worksheet_iterator::operator--()
+{
+    --index_;
+    return *this;
+}
+
+worksheet_iterator worksheet_iterator::operator--(int)
+{
+    worksheet_iterator old(*wb_, index_);
+    --(*this);
+    return old;
+}
+
 bool worksheet_iterator::operator==(const worksheet_iterator &comparand) const
 {
     return index_ == comparand.index_ && wb_ == comparand.wb_;
@@ -65,25 +78,14 @@ bool worksheet_iterator::operator!=(const worksheet_iterator &comparand) const
     return !(*this == comparand);
 }
 
-worksheet_iterator &worksheet_iterator::operator=(const worksheet_iterator &other)
-{
-    index_ = other.index_;
-    return *this;
-}
-
 const_worksheet_iterator::const_worksheet_iterator(const workbook &wb, std::size_t index)
-    : wb_(wb), index_(index)
+    : wb_(&wb), index_(index)
 {
 }
 
-const_worksheet_iterator::const_worksheet_iterator(const const_worksheet_iterator &rhs)
-    : wb_(rhs.wb_), index_(rhs.index_)
+const const_worksheet_iterator::reference const_worksheet_iterator::operator*() const
 {
-}
-
-const worksheet const_worksheet_iterator::operator*()
-{
-    return wb_.sheet_by_index(index_);
+    return wb_->sheet_by_index(index_);
 }
 
 const_worksheet_iterator &const_worksheet_iterator::operator++()
@@ -94,11 +96,24 @@ const_worksheet_iterator &const_worksheet_iterator::operator++()
 
 const_worksheet_iterator const_worksheet_iterator::operator++(int)
 {
-    const_worksheet_iterator old(wb_, index_);
+    const_worksheet_iterator old(*wb_, index_);
     ++*this;
     return old;
 }
 
+const_worksheet_iterator &const_worksheet_iterator::operator--()
+{
+    --index_;
+    return *this;
+}
+
+const_worksheet_iterator const_worksheet_iterator::operator--(int)
+{
+    const_worksheet_iterator old(*wb_, index_);
+    --(*this);
+    return old;
+}
+
 bool const_worksheet_iterator::operator==(const const_worksheet_iterator &comparand) const
 {
     return index_ == comparand.index_ && wb_ == comparand.wb_;

source/worksheet/cell_iterator.cpp

@@ -58,16 +58,6 @@ const_cell_iterator::const_cell_iterator(worksheet ws, const cell_reference &cur
     }
 }
 
-cell_iterator::cell_iterator(const cell_iterator &other)
-{
-    *this = other;
-}
-
-const_cell_iterator::const_cell_iterator(const const_cell_iterator &other)
-{
-    *this = other;
-}
-
 bool cell_iterator::operator==(const cell_iterator &other) const
 {
     return ws_ == other.ws_
@@ -275,14 +265,18 @@ const_cell_iterator const_cell_iterator::operator++(int)
     return old;
 }
 
-cell cell_iterator::operator*()
+cell_iterator::reference cell_iterator::operator*()
 {
     return ws_.cell(cursor_);
 }
 
-const cell const_cell_iterator::operator*() const
+const cell_iterator::reference cell_iterator::operator*() const
 {
     return ws_.cell(cursor_);
 }
 
+const const_cell_iterator::reference const_cell_iterator::operator*() const
+{
+    return ws_.cell(cursor_);
+}
 } // namespace xlnt

source/worksheet/range_iterator.cpp

@@ -28,7 +28,12 @@
 
 namespace xlnt {
 
-cell_vector range_iterator::operator*() const
+range_iterator::reference range_iterator::operator*()
+{
+    return cell_vector(ws_, cursor_, bounds_, order_, skip_null_, false);
+}
+
+const range_iterator::reference range_iterator::operator*() const
 {
     return cell_vector(ws_, cursor_, bounds_, order_, skip_null_, false);
 }
@@ -47,11 +52,6 @@ range_iterator::range_iterator(worksheet &ws, const cell_reference &cursor,
     }
 }
 
-range_iterator::range_iterator(const range_iterator &other)
-{
-    *this = other;
-}
-
 bool range_iterator::operator==(const range_iterator &other) const
 {
     return ws_ == other.ws_
@@ -168,11 +168,6 @@ const_range_iterator::const_range_iterator(const worksheet &ws, const cell_refer
     }
 }
 
-const_range_iterator::const_range_iterator(const const_range_iterator &other)
-{
-    *this = other;
-}
-
 bool const_range_iterator::operator==(const const_range_iterator &other) const
 {
     return ws_ == other.ws_
@@ -274,7 +269,7 @@ const_range_iterator const_range_iterator::operator++(int)
     return old;
 }
 
-const cell_vector const_range_iterator::operator*() const
+const const_range_iterator::reference const_range_iterator::operator*() const
 {
     return cell_vector(ws_, cursor_, bounds_, order_, skip_null_, false);
 }

tests/workbook/workbook_test_suite.hpp

@@ -45,6 +45,7 @@ public:
         register_test(test_index_operator);
         register_test(test_contains);
         register_test(test_iter);
+        register_test(test_const_iter);
         register_test(test_get_index);
         register_test(test_get_sheet_names);
         register_test(test_add_named_range);
@@ -153,17 +154,100 @@ public:
         xlnt_assert(wb.contains("Sheet1"));
         xlnt_assert(!wb.contains("NotThere"));
     }
-    
+
     void test_iter()
     {
         xlnt::workbook wb;
-        
-        for(auto ws : wb)
+
+        for (auto ws : wb)
         {
             xlnt_assert_equals(ws.title(), "Sheet1");
         }
+
+        xlnt::workbook wb2;
+        auto iter = wb.begin();
+        auto iter_copy(iter); // copy ctor
+        xlnt_assert_equals(iter, iter_copy);
+        auto begin_2(wb2.begin());
+        xlnt_assert_differs(begin_2, iter);
+        iter = begin_2; // copy assign
+        xlnt_assert_equals(iter, begin_2);
+        iter = wb.begin();
+        iter = std::move(begin_2);
+        xlnt_assert_equals(iter, wb2.begin());
+
+        auto citer = wb.cbegin();
+        auto citer_copy(citer); // copy ctor
+        xlnt_assert_equals(citer, citer_copy);
+        auto cbegin_2(wb2.cbegin());
+        xlnt_assert_differs(cbegin_2, citer);
+        citer = cbegin_2; // copy assign
+        xlnt_assert_equals(citer, cbegin_2);
+        citer = wb.cbegin();
+        citer = std::move(cbegin_2);
+        xlnt_assert_equals(citer, wb2.cbegin());
+
+        wb2.create_sheet(); // wb2 iterators assumed invalidated
+        iter = wb2.begin();
+        xlnt_assert_equals((*iter).title(), "Sheet1");
+        ++iter;
+        xlnt_assert_differs(iter, wb2.begin());
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        auto temp = --iter;
+        xlnt_assert_equals((*temp).title(), "Sheet1");
+        xlnt_assert_equals((*iter).title(), "Sheet1");
+        iter++;
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        temp = iter++;
+        xlnt_assert_equals((*temp).title(), "Sheet2");
+        xlnt_assert_equals(iter, wb2.end());
+
+        iter = temp--;
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        xlnt_assert_equals((*temp).title(), "Sheet1");
     }
-    
+
+    void test_const_iter()
+    {
+        const xlnt::workbook wb;
+
+        for (auto ws : wb)
+        {
+            xlnt_assert_equals(ws.title(), "Sheet1");
+        }
+
+        xlnt::workbook wb2;
+        auto iter = wb.cbegin();
+        auto iter_copy(iter); // copy ctor
+        xlnt_assert_equals(iter, iter_copy);
+        auto begin_2(wb2.cbegin());
+        xlnt_assert_differs(begin_2, iter);
+        iter = begin_2; // copy assign
+        xlnt_assert_equals(iter, begin_2);
+        iter = wb.cbegin();
+        iter = std::move(begin_2);
+        xlnt_assert_equals(iter, wb2.cbegin());
+        // wb2 iterators assumed invalidated
+        wb2.create_sheet();
+        iter = wb2.cbegin();
+        xlnt_assert_equals((*iter).title(), "Sheet1");
+        ++iter;
+        xlnt_assert_differs(iter, wb2.cbegin());
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        auto temp = --iter;
+        xlnt_assert_equals((*temp).title(), "Sheet1");
+        xlnt_assert_equals((*iter).title(), "Sheet1");
+        iter++;
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        temp = iter++;
+        xlnt_assert_equals((*temp).title(), "Sheet2");
+        xlnt_assert_equals(iter, wb2.cend());
+
+        iter = temp--;
+        xlnt_assert_equals((*iter).title(), "Sheet2");
+        xlnt_assert_equals((*temp).title(), "Sheet1");
+    }
+
     void test_get_index()
     {
         xlnt::workbook wb;