map/multi_fixed: add erase_item

map/multi_fixed.hpp

@@ -261,6 +261,23 @@ namespace cruft::map {
             return tally;
         }
 
+        void
+        erase_item (value_type const &kv)
+        {
+            auto [first, last] = equal_range (kv.first);
+
+            auto const pos = std::find_if (
+                first,
+                last,
+                [&kv] (auto const &candidate) { return candidate.second == kv.second; }
+            );
+
+            if (pos == last)
+                throw std::out_of_range ("unknown key-value");
+
+            erase (pos);
+        }
+
 
         std::size_t erase (key_type const&);