Stop using deprecated std::iterator

As reported in #4615 and others, GCC 12.1 emits deprecation warnings
because we use std::iterator. Replace it with the modern equivalent.

Closes #4615

1 files changed, 6 insertions, 1 deletions

diff --git a/src/regex.hh b/src/regex.hh
index bd32f2d8..5b0ab7fc 100644
--- a/src/regex.hh
+++ b/src/regex.hh
@@ -45,8 +45,13 @@ struct MatchResults
         bool matched = false;
     };
 
-    struct iterator : std::iterator<std::bidirectional_iterator_tag, SubMatch, size_t, SubMatch*, SubMatch>
+    struct iterator
     {
+        using difference_type = size_t;
+        using value_type = SubMatch;
+        using pointer = SubMatch*;
+        using reference = SubMatch;
+        using iterator_category = std::bidirectional_iterator_tag;
         using It = typename Vector<Iterator, MemoryDomain::Regex>::const_iterator;
 
         iterator() = default;