xo-alloc2: + AllocRange aux class, for alloc_range()

include/xo/alloc2/alloc/AAllocator.hpp

@@ -7,7 +7,8 @@
 
 #include "AllocError.hpp"
 #include "AllocInfo.hpp"
-#include "AllocIterator.hpp"
+//#include "AllocIterator.hpp"
+#include "AllocRange.hpp"
 #include <xo/facet/obj.hpp>
 #include <xo/facet/facet_implementation.hpp>
 #include <xo/facet/typeseq.hpp>
@@ -35,7 +36,7 @@ namespace xo {
             /** object header, if configured **/
             using header_type = std::uint64_t;
             /** iterator range. These are forward iterators over allocs **/
-            using range_type = std::pair<obj<AAllocIterator>, obj<AAllocIterator>>;
+            using range_type = AllocRange;
             ///@}
 
             /*

include/xo/alloc2/alloc/AllocRange.hpp

@@ -0,0 +1,34 @@
+/** @file AllocRange.hpp
+ *
+ *  @author Roland Conybeare, Dec 2025
+ **/
+
+#pragma once
+
+#include "AllocIterator.hpp"
+
+namespace xo {
+    namespace mm {
+        /** @class AllocRange
+         *  @brief Provide range iteration over an @ref AAllcator
+         *
+         *  Return value type for @ref AAllocator::alloc_range
+         **/
+        struct AllocRange {
+        public:
+            using repr_type = std::pair<obj<AAllocIterator>, obj<AAllocIterator>>;
+
+        public:
+            AllocRange() = default;
+            explicit AllocRange(repr_type range) : range_{std::move(range)} {}
+
+            obj<AAllocIterator> begin() const { return range_.first; }
+            obj<AAllocIterator>   end() const { return range_.second; }
+
+            /** state: {begin,end} pair of alloc iterators **/
+            repr_type range_;
+        };
+    } /*namsepace mm*/
+} /*namespace xo*/
+
+/* end AllocRange.hpp */

include/xo/alloc2/arena/IAllocator_DArena.hpp

@@ -31,8 +31,7 @@ namespace xo {
              */
             using size_type = std::size_t;
             using value_type = std::byte *;
-            using range_type = std::pair<obj<AAllocIterator>,
-                                         obj<AAllocIterator>>;
+            using range_type = AAllocator::range_type;
 
             static std::string_view name(const DArena &) noexcept;
             static size_type reserved(const DArena &) noexcept;

include/xo/alloc2/gc/IAllocator_DX1Collector.hpp

@@ -31,8 +31,7 @@ namespace xo {
         struct IAllocator_DX1Collector {
             using size_type = std::size_t;
             using value_type = std::byte *;
-            using range_type = std::pair<obj<AAllocIterator>,
-                                         obj<AAllocIterator>>;
+            using range_type = AAllocator::range_type;
 
             // todo: available()