xo-alloc2: rename: AllocatorError -> AllocError

include/xo/alloc2/alloc/AllocInfo.hpp

@@ -0,0 +1,44 @@
+/** @file AllocInfo.hpp
+ *
+ *  @author Roland Conybeare, Dec 2025
+ **/
+
+#pragma once
+
+#include "AllocHeader.hpp"
+
+namespace xo {
+    namespace mm {
+        /** @class AllocInfo
+         *  @brief bookkeeping information for an allocation
+         *
+         *  AllocInfo instances are 1:1 with sum of calls to
+         *  {@ref AAllocator::alloc, @ref AAllocator::alloc_super}
+         *
+         **/
+        struct AllocInfo {
+            using size_type = AllocHeader::size_type;
+
+            AllocInfo(const AllocHeaderConfig * p_cfg, const AllocHeader * p_hdr)
+                : p_config_{p_cfg}, p_header_{p_hdr} {}
+
+            /** error when alloc-header not configured **/
+            static AllocInfo error_not_configured(AllocHeaderConfig * p_cfg) { return AllocInfo(p_cfg, nullptr); }
+
+            /** true for non-sentinel AllocInfo instance **/
+            bool is_valid() const { return (p_config_ != nullptr) && (p_header_ != nullptr); }
+
+            /** Type sequence number in garbage collector **/
+            std::uint32_t tseq() const noexcept { return p_config_->tseq(*p_header_); }
+            /** Allocation age in garbage collector **/
+            std::uint32_t  age() const noexcept { return p_config_->age (*p_header_); }
+            /** Allocation size (including allocator-supplied padding) **/
+            size_type     size() const noexcept { return p_config_->size(*p_header_); }
+
+            const AllocHeaderConfig * p_config_ = nullptr;
+            const AllocHeader *       p_header_ = nullptr;
+        };
+    } /*namespace mm*/
+} /*namespace xo*/
+
+/* end AllocInfo.hpp */