AK+Kernel: Make IntrusiveList capable of holding non-raw pointers

This should allow creating intrusive lists that have smart pointers,
while remaining free (compared to the impl before this commit) when
holding raw pointers :^)
As a sidenote, this also adds a `RawPtr<T>` type, which is just
equivalent to `T*`.
Note that this does not actually use such functionality, but is only
expected to pave the way for #6369, to replace NonnullRefPtrVector<T>
with intrusive lists.

As it is with zero-cost things, this makes the interface a bit less nice
by requiring the type name of what an `IntrusiveListNode` holds (and
optionally its container, if not RawPtr), and also requiring the type of
the container (normally `RawPtr`) on the `IntrusiveList` instance.

1 files changed, 3 insertions, 3 deletions

diff --git a/Kernel/FileSystem/BlockBasedFileSystem.cpp b/Kernel/FileSystem/BlockBasedFileSystem.cpp
index 8bd2e70d00..93fcbff6f9 100644
--- a/Kernel/FileSystem/BlockBasedFileSystem.cpp
+++ b/Kernel/FileSystem/BlockBasedFileSystem.cpp
@@ -32,7 +32,7 @@
 namespace Kernel {
 
 struct CacheEntry {
-    IntrusiveListNode list_node;
+    IntrusiveListNode<CacheEntry> list_node;
     BlockBasedFS::BlockIndex block_index { 0 };
     u8* data { nullptr };
     bool has_data { false };
@@ -117,8 +117,8 @@ private:
     BlockBasedFS& m_fs;
     size_t m_entry_count { 10000 };
     mutable HashMap<BlockBasedFS::BlockIndex, CacheEntry*> m_hash;
-    mutable IntrusiveList<CacheEntry, &CacheEntry::list_node> m_clean_list;
-    mutable IntrusiveList<CacheEntry, &CacheEntry::list_node> m_dirty_list;
+    mutable IntrusiveList<CacheEntry, RawPtr<CacheEntry>, &CacheEntry::list_node> m_clean_list;
+    mutable IntrusiveList<CacheEntry, RawPtr<CacheEntry>, &CacheEntry::list_node> m_dirty_list;
     KBuffer m_cached_block_data;
     KBuffer m_entries;
     bool m_dirty { false };