Adapt FS to tl::identifier no longer having an invalid value

include/fs/CustomFilesystem.h

@@ -23,7 +23,7 @@ public:
 	//////////////////////////////////////////////////////////////////////////
 	// New API
 
-	TL_DECLARE_INTEGRAL_ID(PackId, uint64_t, 0)
+	TL_DECLARE_INTEGRAL_ID(PackId, uint64_t)
 
 	tl::result<PackId> mountFront(AbsPath mountPoint, tl::unique_ref<IPack> pack);
 	tl::result<PackId> mountBack(AbsPath mountPoint, tl::unique_ref<IPack> pack);
@@ -74,8 +74,9 @@ private:
 		tl::unique_ref<IPack> pack;
 		AbsPath mountPoint;
 
-		explicit PackData(tl::unique_ref<IPack>&& pack) noexcept
+		explicit PackData(tl::unique_ref<IPack>&& pack, PackId i_packId) noexcept
 			: pack(std::move(pack))
+			, id(i_packId)
 		{}
 
 		PackData(PackData&& other) noexcept = default;

src/CustomFilesystem.cpp

@@ -575,7 +575,6 @@ void CustomFilesystem::convertToPackPath(AbsPath& packPath, const AbsPath& path,
 
 tl::result<CustomFilesystem::PackId> CustomFilesystem::mount(AbsPath mountPoint, tl::unique_ref<IPack> pack, MountPolicy policy)
 {
-	PackData data(std::move(pack));
 
 	if (!mountPoint.is_valid())
 		return tl::make_generic_error("Invalid mount point");
@@ -585,7 +584,7 @@ tl::result<CustomFilesystem::PackId> CustomFilesystem::mount(AbsPath mountPoint,
 		return tl::make_generic_error("Invalid shadowing (mount point shadowing a file)");
 
 	const PackId id(++s_lastId);
-	data.id = id;
+	PackData data(std::move(pack), id);
 	data.mountPoint = std::move(mountPoint);
 
 	switch (policy)