1 files changed, 22 insertions, 14 deletions
diff --git a/zen/file_id_def.h b/zen/file_id_def.h
index 24e45795..2880121c 100644
--- a/zen/file_id_def.h
+++ b/zen/file_id_def.h
@@ -20,12 +20,28 @@
 namespace zen
 {
 #ifdef ZEN_WIN
-typedef DWORD DeviceId;
-typedef ULONGLONG FileIndex;
+using VolumeId  = DWORD;
+using FileIndex = ULONGLONG;
 
-typedef std::pair<DeviceId, FileIndex> FileId; //optional! (however, always set on Linux, and *generally* available on Windows)
+#elif defined ZEN_LINUX || defined ZEN_MAC
+namespace impl { typedef struct ::stat StatDummy; } //sigh...
+
+using VolumeId  = decltype(impl::StatDummy::st_dev);
+using FileIndex = decltype(impl::StatDummy::st_ino);
+#endif
+
+
+struct FileId  //always available on Linux, and *generally* available on Windows)
+{
+    FileId() {}
+    FileId(VolumeId volId, FileIndex fIdx) : volumeId(volId), fileIndex(fIdx) {}
+    VolumeId  volumeId  = 0;
+    FileIndex fileIndex = 0;
+};
+inline bool operator==(const FileId& lhs, const FileId& rhs) { return lhs.volumeId == rhs.volumeId && lhs.fileIndex == rhs.fileIndex; }
 
 
+#ifdef ZEN_WIN
 inline
 FileId extractFileId(const BY_HANDLE_FILE_INFORMATION& fileInfo)
 {
@@ -44,19 +60,11 @@ FileId extractFileId(DWORD volumeSerialNumber, ULONGLONG fileIndex)
            FileId(volumeSerialNumber, fileIndex) : FileId();
 }
 
-static_assert(sizeof(FileId().first ) == sizeof(BY_HANDLE_FILE_INFORMATION().dwVolumeSerialNumber), "");
-static_assert(sizeof(FileId().second) == sizeof(BY_HANDLE_FILE_INFORMATION().nFileIndexHigh) + sizeof(BY_HANDLE_FILE_INFORMATION().nFileIndexLow), "");
-static_assert(sizeof(FileId().second) == sizeof(ULARGE_INTEGER), "");
-
+static_assert(sizeof(FileId().volumeId ) == sizeof(BY_HANDLE_FILE_INFORMATION().dwVolumeSerialNumber), "");
+static_assert(sizeof(FileId().fileIndex) == sizeof(BY_HANDLE_FILE_INFORMATION().nFileIndexHigh) + sizeof(BY_HANDLE_FILE_INFORMATION().nFileIndexLow), "");
+static_assert(sizeof(FileId().fileIndex) == sizeof(ULARGE_INTEGER), "");
 
 #elif defined ZEN_LINUX || defined ZEN_MAC
-namespace impl { typedef struct ::stat StatDummy; } //sigh...
-
-typedef decltype(impl::StatDummy::st_dev) DeviceId;
-typedef decltype(impl::StatDummy::st_ino) FileIndex;
-
-typedef std::pair<DeviceId, FileIndex> FileId;
-
 inline
 FileId extractFileId(const struct ::stat& fileInfo)
 {