173   // version 12 rejects it.

   173   // version 12 rejects it.

   174 NOT_AIX( private: )

   174 NOT_AIX( private: )

   175   class Block;                  // Forward decl; defined in .inline.hpp file.

   175   class Block;                  // Forward decl; defined in .inline.hpp file.

   176   class BlockList;              // Forward decl for BlockEntry friend decl.

   176   class BlockList;              // Forward decl for BlockEntry friend decl.

   177 

   177 

   179     friend class BlockList;

   179     friend class BlockList;

   180 

   180 

   181     // Members are mutable, and we deal exclusively with pointers to

   181     // Members are mutable, and we deal exclusively with pointers to

   182     // const, to make const blocks easier to use; a block being const

   182     // const, to make const blocks easier to use; a block being const

   183     // doesn't prevent modifying its list state.

   183     // doesn't prevent modifying its list state.

   191   public:

   191   public:

   192     BlockEntry();

   192     BlockEntry();

   193     ~BlockEntry();

   193     ~BlockEntry();

   194   };

   194   };

   195 

   195 

   197     const Block* _head;

   197     const Block* _head;

   198     const Block* _tail;

   198     const Block* _tail;

   199     const BlockEntry& (*_get_entry)(const Block& block);

   199     const BlockEntry& (*_get_entry)(const Block& block);

   200 

   200 

   201     // Noncopyable.

   201     // Noncopyable.