[C++17] Don't inherit from std::iterator...

[ginac.git] / ginac / ex.h

diff --git a/ginac/ex.h b/ginac/ex.h
index 861bf730de695ba023e3bd9979bf2ccad4533098..555de30680443c1d23a8d23d3b0b86d3e8b041fb 100644 (file)
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -367,12 +367,17 @@ bool ex::is_equal(const ex & other) const
 
 // Iterators
 
-class const_iterator : public std::iterator<std::random_access_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
+class const_iterator {
        friend class ex;
        friend class const_preorder_iterator;
        friend class const_postorder_iterator;
-
 public:
+       using iterator_category = std::random_access_iterator_tag;
+       using value_type = ex;
+       using difference_type = ptrdiff_t;
+       using pointer = const ex *;
+       using reference = const ex &;
+
        const_iterator() noexcept {}
 
 private:
@@ -513,8 +518,13 @@ struct _iter_rep {
 
 } // namespace internal
 
-class const_preorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
+class const_preorder_iterator {
 public:
+       using iterator_category = std::forward_iterator_tag;
+       using value_type = ex;
+       using difference_type = ptrdiff_t;
+       using pointer = const ex *;
+       using reference = const ex &;
        const_preorder_iterator() noexcept {}
 
        const_preorder_iterator(const ex &e, size_t n)
@@ -577,8 +587,13 @@ private:
        }
 };
 
-class const_postorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
+class const_postorder_iterator {
 public:
+       using iterator_category = std::forward_iterator_tag;
+       using value_type = ex;
+       using difference_type = ptrdiff_t;
+       using pointer = const ex *;
+       using reference = const ex &;
        const_postorder_iterator() noexcept {}
 
        const_postorder_iterator(const ex &e, size_t n)