Define ArchiveMember structure

CMakePresets.json

@@ -99,7 +99,7 @@
     {
       "name": "ci-win64",
       "inherits": ["flags-msvc", "ci-std"],
-      "generator": "Visual Studio 17 2022",
+      "generator": "Visual Studio 18 2026",
       "architecture": "x64",
       "hidden": true
     },

include/ifc/file.hxx

@@ -205,6 +205,17 @@ namespace ifc {
         }
     };
 
+    // -- ToC entry for a member of an archive IFC.
+    // -- When header.unit.sort() == UnitSort::Archive, header.toc addresses header.partition_count
+    // -- of these, sorted by canonical name with sort() being tie-breaker.
+    struct ArchiveMember {
+        UnitIndex name;         // canonical name; with `sort` -- member's identity.
+        TextOffset path;        // path to the member's IFC container when it was embedded.
+        ByteOffset offset;      // location of the member within the archive
+        EntitySize size;        // size of the member in bytes count.
+    };
+    static_assert(sizeof(ArchiveMember) == 16);
+
     // Exception tag used to signal target architecture mismatch.
     struct IfcArchMismatch {
         Pathname name;

test/basic.cxx

@@ -308,8 +308,8 @@ TEST_CASE("IFC spec - Test header")
     InputIfc ifc;
     Reader reader = create_ifc_reader(IFC_FILE, &buf, &ifc);
 
-    // The currently documented version of the IFC that the MSVC compiler will emit is 0.43.
-    constexpr auto expected_version = FormatVersion{ Version{ 0 }, Version{ 43 } };
+    // The currently documented version of the IFC that the MSVC compiler will emit is 0.44.
+    constexpr auto expected_version = FormatVersion{ Version{ 0 }, Version{ 44 } };
     CHECK_MESSAGE(reader.ifc.header()->version == expected_version, "minor/major");
     CHECK_MESSAGE(reader.ifc.header()->abi == Abi{}, "abi - not currently set in MSVC");
     // arch - since we compile this file in multiple modes, let's just ensure that 'arch' matches one of the known types.