- //===- llvm/ADT/ilist_base.h - Intrusive List Base --------------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_ADT_ILIST_BASE_H 
- #define LLVM_ADT_ILIST_BASE_H 
-   
- #include "llvm/ADT/ilist_node_base.h" 
- #include <cassert> 
-   
- namespace llvm { 
-   
- /// Implementations of list algorithms using ilist_node_base. 
- template <bool EnableSentinelTracking> class ilist_base { 
- public: 
-   using node_base_type = ilist_node_base<EnableSentinelTracking>; 
-   
-   static void insertBeforeImpl(node_base_type &Next, node_base_type &N) { 
-     node_base_type &Prev = *Next.getPrev(); 
-     N.setNext(&Next); 
-     N.setPrev(&Prev); 
-     Prev.setNext(&N); 
-     Next.setPrev(&N); 
-   } 
-   
-   static void removeImpl(node_base_type &N) { 
-     node_base_type *Prev = N.getPrev(); 
-     node_base_type *Next = N.getNext(); 
-     Next->setPrev(Prev); 
-     Prev->setNext(Next); 
-   
-     // Not strictly necessary, but helps catch a class of bugs. 
-     N.setPrev(nullptr); 
-     N.setNext(nullptr); 
-   } 
-   
-   static void removeRangeImpl(node_base_type &First, node_base_type &Last) { 
-     node_base_type *Prev = First.getPrev(); 
-     node_base_type *Final = Last.getPrev(); 
-     Last.setPrev(Prev); 
-     Prev->setNext(&Last); 
-   
-     // Not strictly necessary, but helps catch a class of bugs. 
-     First.setPrev(nullptr); 
-     Final->setNext(nullptr); 
-   } 
-   
-   static void transferBeforeImpl(node_base_type &Next, node_base_type &First, 
-                                  node_base_type &Last) { 
-     if (&Next == &Last || &First == &Last) 
-       return; 
-   
-     // Position cannot be contained in the range to be transferred. 
-     assert(&Next != &First && 
-            // Check for the most common mistake. 
-            "Insertion point can't be one of the transferred nodes"); 
-   
-     node_base_type &Final = *Last.getPrev(); 
-   
-     // Detach from old list/position. 
-     First.getPrev()->setNext(&Last); 
-     Last.setPrev(First.getPrev()); 
-   
-     // Splice [First, Final] into its new list/position. 
-     node_base_type &Prev = *Next.getPrev(); 
-     Final.setNext(&Next); 
-     First.setPrev(&Prev); 
-     Prev.setNext(&First); 
-     Next.setPrev(&Final); 
-   } 
-   
-   template <class T> static void insertBefore(T &Next, T &N) { 
-     insertBeforeImpl(Next, N); 
-   } 
-   
-   template <class T> static void remove(T &N) { removeImpl(N); } 
-   template <class T> static void removeRange(T &First, T &Last) { 
-     removeRangeImpl(First, Last); 
-   } 
-   
-   template <class T> static void transferBefore(T &Next, T &First, T &Last) { 
-     transferBeforeImpl(Next, First, Last); 
-   } 
- }; 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_ADT_ILIST_BASE_H 
-