bslalg_hashtableanchor.h

Go to the documentation of this file.

/// @file bslalg_hashtableanchor.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslalg_hashtableanchor.h                                           -*-C++-*-
#ifndef INCLUDED_BSLALG_HASHTABLEANCHOR
#define INCLUDED_BSLALG_HASHTABLEANCHOR
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslalg_hashtableanchor bslalg_hashtableanchor
/// @brief  Provide a type holding the constituent parts of a hash table.
/// @addtogroup bsl
/// @{
/// @addtogroup bslalg
/// @{
/// @addtogroup bslalg_hashtableanchor
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslalg_hashtableanchor-purpose"> Purpose</a>
/// * <a href="#bslalg_hashtableanchor-classes"> Classes </a>
/// * <a href="#bslalg_hashtableanchor-description"> Description </a>
///   * <a href="#bslalg_hashtableanchor-attributes"> Attributes </a>
///   * <a href="#bslalg_hashtableanchor-usage"> Usage </a>
///     * <a href="#bslalg_hashtableanchor-example-1-basic-usage"> Example 1: Basic Usage </a>
///
/// # Purpose {#bslalg_hashtableanchor-purpose}
/// Provide a type holding the constituent parts of a hash table.
///
/// # Classes {#bslalg_hashtableanchor-classes}
///
/// - bslalg::HashTableAnchor: (in-core) bucket-array and node list
///
/// @see  bslstl_hashtable, bslalg_hashtableimputil
///
/// # Description {#bslalg_hashtableanchor-description}
/// This component provides a single, complex-constrained
/// **in-core** (value-semantic) attribute class, `bslalg::HashTableAnchor`,
/// that is used to hold (not own) the array of buckets and the list of nodes
/// that form the key data elements of a hash-table.  This class is typically
/// used with the utilities provided in @ref bslstl_hashtableimputil .  Note that
/// the decision to store nodes in a linked list (i.e., resolving collisions
/// through chaining) is intended to facilitate a hash-table implementation
/// meeting the requirements of a C++11 standard unordered container.
///
/// ## Attributes {#bslalg_hashtableanchor-attributes}
///
///
/// @code
/// Name                Type                  Simple Constraints
/// ------------------  -------------------   ------------------
/// bucketArrayAddress  HashTableBucket *     none
///
/// bucketArraySize     size_t                none
///
/// listRootAddress     BidirectionalLink *   none
///
///
/// Complex Constraint
/// -------------------------------------------------------------------------
/// `bucketArrayAddress` must refer to a contiguous sequence of valid
/// `bslalg::HashTableBucket` objects of at least the specified
/// `bucketArraySize` or both `bucketArrayAddress` and `bucketArraySize` must
/// be 0.
/// @endcode
///
/// * `listRootAddress`: address of the head of the linked list of nodes
///   holding the elements contained in a hash table
/// * `bucketArrayAddress`: address of the first element of the sequence of
///   `HashTableBucket` objects, each of which refers to the first and last
///   node (from `listRootAddress`) in that bucket
/// * `bucketArraySize`: the number of (contiguous) buckets in the array of
///   buckets at `bucketArrayAddress`
///
/// ## Usage {#bslalg_hashtableanchor-usage}
///
///
/// This section illustrates intended use of this component.
///
/// ### Example 1: Basic Usage {#bslalg_hashtableanchor-example-1-basic-usage}
///
///
/// Suppose we want to create a hash table that keeps track of pointers.
/// Pointers can be added (`insert`ed) or removed (`erase`d) from the table, and
/// the table will keep track, at any time, of whether a pointer is currently
/// stored in the table using the `count` method.  It will also be able to
/// return the total number of objects stored in the table (the `size` method).
/// Redundant `insert`s have no effect -- a given pointer may only be stored in
/// the table once.
///
/// First, we create our class:
/// @code
/// class PtrHashSet : public bslalg::HashTableAnchor {
///     // PRIVATE TYPES
///     typedef bsls::Types::UintPtr              UintPtr;
///     typedef bslalg::BidirectionalNode<void *> Node;
///     typedef bslalg::HashTableBucket           Bucket;
///     typedef bslalg::BidirectionalLinkListUtil Util;
///
///     // DATA
///     double            d_maxLoadFactor;
///     unsigned          d_numNodes;
///     bslma::Allocator *d_allocator_p;
///
///     // PRIVATE MANIPULATORS
///
///     /// Roughly double the number of buckets, such that the number of
///     /// buckets shall always be `2^N - 1`.
///     void grow();
///
///     // PRIVATE ACCESSORS
///
///     /// Perform sanity checks on this table, returning `true` if all the
///     /// tests pass and `false` otherwise.  Note that many of the checks
///     /// are done with the `ASSERTV` macro and will cause messages to be
///     /// written to the console.
///     bool checkInvariants() const;
///
///     /// If the specified value `ptr` is stored in this table, return
///     /// pointers to its node and bucket in the specified 'node' and
///     /// `bucket`.  If it is not in this table, return the bucket it
///     /// should be in, and a pointer to the first node, if any, in that
///     /// bucket.  If the bucket is empty, return with
///     /// `*node == listRootAddress()`.  Return `true` if `ptr` was found
///     /// in the table and `false` otherwise.  Note that it is permissible
///     /// to pass 0 to `node` and / or `bucket`, in which case these
///     /// arguments are ignored.
///     bool find(Node **node, Bucket **bucket, const void *ptr) const;␇
///
///   private:
///     // NOT IMPLEMENTED
///     PtrHashSet(const PtrHashSet&, bslma::Allocator *);
///     PtrHashSet& operator=(const PtrHashSet&);
///
///   public:
///     // CREATORS
///
///     /// Create a `PtrHashSet`, using the specified `allocator`.  If no
///     /// allocator is specified, use the default allocator.
///     explicit
///     PtrHashSet(bslma::Allocator *allocator = 0);
///
///     /// Destroy this `PtrHashSet`, freeing all its memory.
///     ~PtrHashSet();
///
///     // MANIPULATORS
///
///     /// If the specfied `ptr` is not in this hash table, add it,
///     /// returning `true`.  If it is already in the table, return `false`
///     /// with no action taken.
///     bool insert(void *ptr);
///
///     /// If the specfied `ptr` is in this hash table, remove it,
///     /// returning `true`.  If it is not found in the table, return
///     /// `false` with no action taken.
///     bool erase(void *ptr);
///
///     // ACCESSORS
///
///     /// Return 1 if the specified value `ptr` is in this table and 0
///     /// otherwise.
///     std::size_t count(void *ptr) const;
///
///     /// Return the number of discrete values that are stored in this
///     /// table.
///     std::size_t size() const;
/// };
///
/// // PRIVATE MANIPULATORS
/// void PtrHashSet::grow()
/// {
///     // 'bucketArraySize' will always be '2^N - 1', so that when pointers
///     // are aligned by some 2^N they're likely to be relatively prime.
///
///     std::size_t newBucketArraySize = bucketArraySize() * 2 + 1;
///     std::size_t newBucketArraySizeInBytes =
///                                        newBucketArraySize * sizeof(Bucket);
///     memset(bucketArrayAddress(), 0x5a, size() * sizeof(Bucket));
///     d_allocator_p->deallocate(bucketArrayAddress());
///     setBucketArrayAddressAndSize(
///              (Bucket *) d_allocator_p->allocate(newBucketArraySizeInBytes),
///              newBucketArraySize);
///     memset(bucketArrayAddress(), 0, newBucketArraySizeInBytes);
///     Node *newListRootAddress = 0;
///
///     unsigned numNodes = 0;
///     for (Node *node = (Node *) listRootAddress(); node; ++numNodes) {
///         Node *rippedOut = node;
///         node = (Node *) node->nextLink();
///
///         std::size_t index =
///                           (UintPtr) rippedOut->value() % bucketArraySize();
///         Bucket& bucket = bucketArrayAddress()[index];
///         if (bucket.first()) {
///             if (0 == bucket.first()->previousLink()) {
///                 newListRootAddress = rippedOut;
///             }
///             Util::insertLinkBeforeTarget(rippedOut, bucket.first());
///             bucket.setFirst(rippedOut);
///         }
///         else {
///             Util::insertLinkBeforeTarget(rippedOut,
///                                          newListRootAddress);
///             newListRootAddress = rippedOut;
///             bucket.setFirstAndLast(rippedOut, rippedOut);
///         }
///     }
///     assert(size() == numNodes);
///
///     setListRootAddress(newListRootAddress);
///
///     checkInvariants();
/// }
///
/// // PRIVATE ACCESSORS
/// bool PtrHashSet::checkInvariants() const
/// {
///     bool ok;
///
///     unsigned numNodes = 0;
///     Node *prev = 0;
///     for (Node *node = (Node *) listRootAddress(); node;
///                            prev = node, node = (Node *) node->nextLink()) {
///         ok = node->previousLink() == prev;
///         assert(ok && "node->previousLink() == prev");
///         if (!ok) return false;                                    // RETURN
///         ++numNodes;
///     }
///     ok = size() == numNodes;
///     assert(ok && "size() == numNodes");
///     if (!ok) return false;                                        // RETURN
///
///     numNodes = 0;
///     for (unsigned i = 0; i < bucketArraySize(); ++i) {
///         Bucket& bucket = bucketArrayAddress()[i];
///         if (bucket.first()) {
///             ++numNodes;
///             for (Node *node = (Node *) bucket.first();
///                               bucket.last() != node;
///                                         node = (Node *) node->nextLink()) {
///                 ++numNodes;
///             }
///         }
///         else {
///             ok = !bucket.last();
///             assert(ok && "!bucket.last()");
///             if (!ok) return false;                                // RETURN
///         }
///     }
///     ok = size() == numNodes;
///     assert(ok && "size() == numNodes");
///
///     return ok;
/// }
///
/// bool PtrHashSet::find(Node **node, Bucket **bucket, const void *ptr) const
/// {
///     Node   *dummyNodePtr;
///     Bucket *dummyBucketPtr;
///     if (!node  ) node   = &dummyNodePtr;
///     if (!bucket) bucket = &dummyBucketPtr;
///
///     Node *& nodePtrRef = *node;
///     unsigned index = (UintPtr) ptr % bucketArraySize();
///     Bucket& bucketRef = bucketArrayAddress()[index];
///     *bucket = &bucketRef;
///     if (bucketRef.first()) {
///         Node *begin      = (Node *) bucketRef.first();
///         Node * const end = (Node *) bucketRef.last()->nextLink();
///         for (Node *n = begin; end != n; n = (Node *) n->nextLink()) {
///             if (n->value() == ptr) {
///                 // found
///
///                 nodePtrRef = n;
///                 return true;                                      // RETURN
///             }
///         }
///         // not found
///
///         nodePtrRef = begin;
///         return false;                                             // RETURN
///     }
///     // empty bucket
///
///     nodePtrRef = (Node *) listRootAddress();
///     return false;
/// }
///
/// // CREATORS
/// PtrHashSet::PtrHashSet(bslma::Allocator *allocator)
/// : HashTableAnchor(0, 0, 0)
/// , d_maxLoadFactor(0.4)
/// , d_numNodes(0)
/// {
///     enum { NUM_BUCKETS = 3 };
///
///     d_allocator_p = bslma::Default::allocator(allocator);
///     std::size_t bucketArraySizeInBytes = NUM_BUCKETS * sizeof(Bucket);
///
///     setBucketArrayAddressAndSize(
///                 (Bucket *) d_allocator_p->allocate(bucketArraySizeInBytes),
///                 NUM_BUCKETS);
///     memset(bucketArrayAddress(), 0, bucketArraySizeInBytes);
/// }
///
/// PtrHashSet::~PtrHashSet()
/// {
///     BSLS_ASSERT_SAFE(checkInvariants());
///
///     for (Node *node = (Node *) listRootAddress(); node; ) {
///         Node *toDelete = node;
///         node = (Node *) node->nextLink();
///
///         memset(toDelete, 0x5a, sizeof(*toDelete));
///         d_allocator_p->deallocate(toDelete);
///     }
///
///     d_allocator_p->deallocate(bucketArrayAddress());
/// }
///
/// // MANIPULATORS
/// bool PtrHashSet::erase(void *ptr)
/// {
///     Bucket *bucket;
///     Node   *node;
///
///     if (!find(&node, &bucket, ptr)) {
///         return false;                                             // RETURN
///     }
///
///     if (bucket->first() == node) {
///         if (bucket->last() == node) {
///             bucket->reset();
///         }
///         else {
///             bucket->setFirst(node->nextLink());
///         }
///     }
///     else if (bucket->last() == node) {
///         bucket->setLast(node->previousLink());
///     }
///
///     --d_numNodes;
///     Util::unlink(node);
///
///     d_allocator_p->deallocate(node);
///
///     checkInvariants();
///
///     return true;
/// }
///
/// bool PtrHashSet::insert(void *ptr)
/// {
///     Bucket *bucket;
///     Node *insertionPoint;
///
///     if (find(&insertionPoint, &bucket, ptr)) {
///         // Already in set, do nothing.
///
///         return false;                                             // RETURN
///     }
///
///     if (bucketArraySize() * d_maxLoadFactor < d_numNodes + 1) {
///         grow();
///         bool found = find(&insertionPoint, &bucket, ptr);
///         BSLS_ASSERT_SAFE(!found);
///     }
///
///     ++d_numNodes;
///     Node *node = (Node *) d_allocator_p->allocate(sizeof(Node));
///
///     Util::insertLinkBeforeTarget(node, insertionPoint);
///     node->value() = ptr;
///     if (listRootAddress() == insertionPoint) {
///         BSLS_ASSERT_SAFE(0 == node->previousLink());
///         setListRootAddress(node);
///     }
///
///     if (bucket->first()) {
///         BSLS_ASSERT_SAFE(bucket->first() == insertionPoint);
///
///         bucket->setFirst(node);
///     }
///     else {
///         BSLS_ASSERT_SAFE(!bucket->last());
///
///         bucket->setFirstAndLast(node, node);
///     }
///
///     assert(count(ptr));
///
///     checkInvariants();
///
///     return true;
/// }
///
/// // ACCESSORS
/// std::size_t PtrHashSet::count(void *ptr) const
/// {
///     return find(0, 0, ptr);
/// }
///
/// std::size_t PtrHashSet::size() const
/// {
///     return d_numNodes;
/// }
/// @endcode
/// Then, in `main`, we create a test allocator for use in this example to
/// ensure that no memory is leaked:
/// @code
/// bslma::TestAllocator ta("test", veryVeryVeryVerbose);
/// @endcode
/// Next, we declare our table using that allocator:
/// @code
/// PtrHashSet phs(&ta);
/// @endcode
/// Then, we create an area of memory from which our pointers will come:
/// @code
/// enum { SEGMENT_LENGTH = 1000 };
/// char *pc = (char *) ta.allocate(SEGMENT_LENGTH);
/// @endcode
/// Next, we iterate through the length of the segment, insert those pointers
/// for which `ptr - pc == N * 7` is true.  We keep a count of the number of
/// items we insert into the table in the variable `sevens`:
/// @code
/// unsigned sevens = 0;
/// for (int i = 0; i < SEGMENT_LENGTH; i += 7) {
///     ++sevens;
///     bool status = phs.insert(&pc[i]);
///     assert(status);
/// }
/// @endcode
/// Then, we verify the number of objects we've placed in the table:
/// @code
/// assert(phs.size() == sevens);
/// @endcode
/// Next, we iterate through ALL pointers in the `pc` array, using the `count`
/// method to verify that the ones we expect are in the table:
/// @code
/// for (int i = 0; i < SEGMENT_LENGTH; ++i) {
///     assert(phs.count(&pc[i]) == (0 == i % 7));
/// }
/// @endcode
/// Then, we iterate, deleting all elements from the table for which
/// `ptr - pc == 3 * N` is true.  We keep a count of the number of elements that
/// were deleted from the table in the variable `killed`:
/// @code
/// unsigned killed = 0;
/// for (int i = 0; i < SEGMENT_LENGTH; i += 3) {
///     const bool deleted = phs.erase(&pc[i]);
///     assert(deleted == (0 == i % 7));
///     killed += deleted;
/// }
/// @endcode
/// Next, we verify the number of remaining elements in the table:
/// @code
/// assert(killed < sevens);
/// assert(phs.size() == sevens - killed);
/// @endcode
/// Then, in verbose mode we print our tallies:
/// @code
/// if (verbose) {
///     printf("sevens = %u, killed = %u, phs.size() = %u\n", sevens,
///            killed, (unsigned) phs.size());
/// }
/// @endcode
/// Now, we iterate through every element of the `pc` array, verifying that the
/// surviving elements are exactly those for which `ptr - pc` was divisible by 7
/// and not by 3:
/// @code
/// for (int i = 0; i < SEGMENT_LENGTH; ++i) {
///     const bool present = phs.count(&pc[i]);
///     assert(present == ((0 == i % 7) && (0 != i % 3)));
/// }
/// @endcode
/// Finally, we clean up our `pc` array:
/// @code
/// ta.deallocate(pc);
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslalg
 * @{
 */
/** @addtogroup bslalg_hashtableanchor
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslalg_bidirectionallink.h>
#include <bslalg_scalarprimitives.h>
 
#include <bslmf_isbitwisecopyable.h>
#include <bslmf_nestedtraitdeclaration.h>
 
#include <bsls_assert.h>
 
#include <cstddef>
 
#ifndef BDE_DONT_ALLOW_TRANSITIVE_INCLUDES
#include <bsls_nativestd.h>
#endif // BDE_DONT_ALLOW_TRANSITIVE_INCLUDES
 
 
 
namespace bslalg {
 
struct HashTableBucket;  // This is known to be a POD struct.
 
                        // =============================
                        // class bslalg::HashTableAnchor
                        // =============================
 
/// This complex constrained *in*-*core* (value-semantic) attribute class
/// characterizes the key data elements of a hash table.  See the
/// @ref bslalg_hashtableanchor-attributes  section information on the class attributes.  Note that the
/// class invariant is the identically the complex constraint of this
/// component.
///
/// This class:
/// * supports a complete set of *value-semantic* operations
///   - except for `bdex` serialization and default construction
/// * is **in-core**
/// * is **exception-neutral** (agnostic)
/// * is **alias-safe**
/// * is `const` **thread-safe**
/// For terminology see @ref bsldoc_glossary .
///
/// See @ref bslalg_hashtableanchor 
class HashTableAnchor {
 
    // DATA
    HashTableBucket     *d_bucketArrayAddress_p;  // address of the array of
                                                  // buckets (held, not owned)
 
    std::size_t          d_bucketArraySize;       // size of 'd_bucketArray'
 
    BidirectionalLink   *d_listRootAddress_p;     // head of the list of
                                                  // elements in the hash-table
                                                  // (held, not owned)
 
  public:
    // TRAITS
    BSLMF_NESTED_TRAIT_DECLARATION(HashTableAnchor,
                                   bslmf::IsBitwiseCopyable);
 
    // CREATORS
 
    /// Create a `bslalg::HashTableAnchor` object having the specified
    /// `bucketArrayAddress`, `bucketArraySize`, and `listRootAddress`
    /// attributes.  The behavior is undefined unless `bucketArrayAddress`
    /// refers to a contiguous sequence of valid `bslalg::HashTableBucket`
    /// objects of at least `bucketArraySize` or unless both
    /// `bucketArrayAddress` and `bucketArraySize` are 0.
    HashTableAnchor(HashTableBucket   *bucketArrayAddress,
                    std::size_t        bucketArraySize,
                    BidirectionalLink *listRootAddress);
 
    /// Create a `bslalg::HashTableAnchor` object having the same value
    /// as the specified `original` object.
    HashTableAnchor(const HashTableAnchor& original);
 
    /// Destroy this object.
     ~bslalg::HashTableAnchor(); = default
 
    // MANIPULATORS
 
    /// Assign to this object the value of the specified `rhs` object, and
    /// return a reference providing modifiable access to this object.
    bslalg::HashTableAnchor& operator=(const bslalg::HashTableAnchor& rhs);
 
    /// Set the bucket array address and bucket array size attributes of
    /// this object to the specified `bucketArrayAddress` and
    /// `bucketArraySize` values.  The behavior is undefined unless
    /// `bucketArrayAddress` refers to a contiguous sequence of valid
    /// `bslalg::HashTableBucket` objects of at least `bucketArraySize`, or
    /// unless both `bucketArrayAddress` and `bucketArraySize` are 0.
    void setBucketArrayAddressAndSize(HashTableBucket *bucketArrayAddress,
                                      std::size_t      bucketArraySize);
 
    /// Set the `listRootAddress` attribute of this object to the
    /// specified `value`.
    void setListRootAddress(BidirectionalLink *value);
 
                                  // Aspects
 
    /// Efficiently exchange the value of this object with the value of the
    /// specified `other` object.  This method provides the no-throw
    /// exception-safety guarantee.
    void swap(HashTableAnchor& other);
 
    // ACCESSORS
 
    /// Return the value of the `bucketArrayAddress` attribute of this
    /// object.
    HashTableBucket *bucketArrayAddress() const;
 
    /// Return the value of the `bucketArraySize` attribute of this object.
    std::size_t bucketArraySize() const;
 
    /// Return the value `listRootAddress` attribute of this object.
    BidirectionalLink *listRootAddress() const;
};
 
// FREE OPERATORS
 
/// Return `true` if the specified `lhs` and `rhs` objects have the same value,
/// and `false` otherwise.  Two `bslalg::HashTableAnchor` objects have the same
/// value if all of the corresponding values of their `bucketArrayAddress`,
/// `bucketArraySize`, and `listRootAddress` attributes are the same.
bool operator==(const HashTableAnchor& lhs, const HashTableAnchor& rhs);
 
/// Return `true` if the specified `lhs` and `rhs` objects do not have the same
/// value, and `false` otherwise.  Two `bslalg::HashTableAnchor` objects do not
/// have the same value if any of the corresponding values of their
/// `bucketArrayAddress`, `bucketArraySize`, or `listRootAddress` attributes
/// are not the same.
bool operator!=(const HashTableAnchor& lhs, const HashTableAnchor& rhs);
 
// FREE FUNCTIONS
 
/// Efficiently exchange the values of the specified `a` and `b` objects.  This
/// function provides the no-throw exception-safety guarantee.  The behavior is
/// undefined unless the two objects were created with the same allocator.
void swap(HashTableAnchor& a, HashTableAnchor& b);
 
// ============================================================================
//                      INLINE FUNCTION DEFINITIONS
// ============================================================================
 
                        // -----------------------------
                        // class bslalg::HashTableAnchor
                        // -----------------------------
 
// CREATORS
inline
HashTableAnchor::HashTableAnchor(bslalg::HashTableBucket   *bucketArrayAddress,
                                 std::size_t                bucketArraySize,
                                 bslalg::BidirectionalLink *listRootAddress)
: d_bucketArrayAddress_p(bucketArrayAddress)
, d_bucketArraySize(bucketArraySize)
, d_listRootAddress_p(listRootAddress)
{
    BSLS_ASSERT_SAFE(   (!bucketArrayAddress && !bucketArraySize)
                     || (bucketArrayAddress && 0 < bucketArraySize));
    BSLS_ASSERT_SAFE(!listRootAddress || !(listRootAddress->previousLink()));
}
 
inline
HashTableAnchor::HashTableAnchor(const HashTableAnchor& original)
: d_bucketArrayAddress_p(original.d_bucketArrayAddress_p)
, d_bucketArraySize(original.d_bucketArraySize)
, d_listRootAddress_p(original.d_listRootAddress_p)
{
}
 
// MANIPULATORS
inline
HashTableAnchor& HashTableAnchor::operator=(const HashTableAnchor& rhs)
{
    d_bucketArrayAddress_p = rhs.d_bucketArrayAddress_p;
    d_bucketArraySize      = rhs.d_bucketArraySize;
    d_listRootAddress_p    = rhs.d_listRootAddress_p;
    return *this;
}
 
inline
void HashTableAnchor::setBucketArrayAddressAndSize(
                                           HashTableBucket *bucketArrayAddress,
                                           std::size_t      bucketArraySize)
{
    BSLS_ASSERT_SAFE(( bucketArrayAddress && 0 < bucketArraySize)
                  || (!bucketArrayAddress &&    !bucketArraySize));
 
    d_bucketArrayAddress_p = bucketArrayAddress;
    d_bucketArraySize      = bucketArraySize;
}
 
inline
void HashTableAnchor::setListRootAddress(BidirectionalLink *value)
{
    BSLS_ASSERT_SAFE(!value || !value->previousLink());
 
    d_listRootAddress_p = value;
}
 
                                  // Aspects
 
inline
void HashTableAnchor::swap(HashTableAnchor& other)
{
    bslalg::ScalarPrimitives::swap(*this, other);
}
 
// ACCESSORS
inline
BidirectionalLink *HashTableAnchor::listRootAddress() const
{
    return d_listRootAddress_p;
}
 
inline
std::size_t HashTableAnchor::bucketArraySize() const
{
    return d_bucketArraySize;
}
 
inline
HashTableBucket *HashTableAnchor::bucketArrayAddress() const
{
    return d_bucketArrayAddress_p;
}
 
}  // close package namespace
 
// FREE OPERATORS
inline
void bslalg::swap(bslalg::HashTableAnchor& a, bslalg::HashTableAnchor& b)
{
    a.swap(b);
}
 
inline
bool bslalg::operator==(const bslalg::HashTableAnchor& lhs,
                        const bslalg::HashTableAnchor& rhs)
{
    return lhs.bucketArrayAddress() == rhs.bucketArrayAddress()
        && lhs.bucketArraySize()    == rhs.bucketArraySize()
        && lhs.listRootAddress()    == rhs.listRootAddress();
}
 
inline
bool bslalg::operator!=(const bslalg::HashTableAnchor& lhs,
                        const bslalg::HashTableAnchor& rhs)
{
    return lhs.bucketArrayAddress() != rhs.bucketArrayAddress()
        || lhs.bucketArraySize()    != rhs.bucketArraySize()
        || lhs.listRootAddress()    != rhs.listRootAddress();
}
 
 
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2013 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
 
/** @} */
/** @} */
/** @} */