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/*!

    \class Q3MemArray

    \brief The Q3MemArray class is a template class that provides arrays of simple types.

    \compat

    Q3MemArray is implemented as a template class. Define a template

    instance Q3MemArray\<X\> to create an array that contains X items.

    Q3MemArray stores the array elements directly in the array. It can

    only deal with simple types (i.e. C++ types, structs, and classes

    that have no constructors, destructors, or virtual functions).

    Q3MemArray uses bitwise operations to copy and compare array

    elements. 

    The Q3PtrVector collection class is also a kind of array. Like most

    old Qt collection classes, it uses pointers to the contained items.

    Q3MemArray uses explicit sharing with a

    reference count. If more than one array shares common data and one

    of the arrays is modified, all the arrays are modified.

    The benefit of sharing is that a program does not need to duplicate

    data when it is not required, which results in lower memory use

    and less copying of data.

    Example:

    \snippet doc/src/snippets/code/doc_src_q3memarray.qdoc 0

    Program output:

    \snippet doc/src/snippets/code/doc_src_q3memarray.qdoc 1

    Note concerning the use of Q3MemArray for manipulating structs or

    classes: Compilers will often pad the size of structs of odd sizes

    up to the nearest word boundary. This will then be the size

    Q3MemArray will use for its bitwise element comparisons. Because

    the remaining bytes will typically be uninitialized, this can

    cause find() etc. to fail to find the element. Example:

    \snippet doc/src/snippets/code/doc_src_q3memarray.qdoc 2

    To work around this, make sure that you use a struct where

    sizeof() returns the same as the sum of the sizes of the members

    either by changing the types of the struct members or by adding

    dummy members.

    Q3MemArray data can be traversed by iterators (see begin() and

    end()). The number of items is returned by count(). The array can

    be resized with resize() and filled using fill().

    You can make a shallow copy of the array with assign() (or

    operator=()) and a deep copy with duplicate().

    Search for values in the array with find() and contains(). For

    sorted arrays (see sort()) you can search using bsearch().

    You can set the data directly using setRawData() and

    resetRawData(), although this requires care.

*/

/*! \fn Q3MemArray::operator QVector<type>() const

    Automatically converts the Q3MemArray<type> into a QVector<type>.

*/

/*! \typedef Q3MemArray::Iterator

    A Q3MemArray iterator.

    \sa begin() end()

*/

/*! \typedef Q3MemArray::ConstIterator

    A const Q3MemArray iterator.

    \sa begin() end()

*/

/*! \typedef Q3MemArray::ValueType

    \internal

*/

/*!

    \fn Q3MemArray::Q3MemArray()

    Constructs a null array.

    \sa isNull()

*/

/*!

    \fn Q3MemArray::Q3MemArray( int size )

    Constructs an array with room for \a size elements. Makes a null

    array if \a size == 0.

    The elements are left uninitialized.

    \sa resize(), isNull()

*/

/*!

    \fn Q3MemArray::Q3MemArray( const Q3MemArray<type> &a )

    Constructs a shallow copy of \a a.

    \sa assign()

*/

/*!

    \fn Q3MemArray::Q3MemArray(const QVector<type> &vector)

    Constructs a copy of \a vector.

*/

/*!

    \fn Q3MemArray::Q3MemArray(int arg1, int arg2)

    Constructs an array \e{without allocating} array space. The

    arguments \a arg1 and \a arg2 should be zero. Use at your own

    risk.

*/

/*!

    \fn Q3MemArray::~Q3MemArray()

    Dereferences the array data and deletes it if this was the last

    reference.

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::operator=( const Q3MemArray<type> &a )

    Assigns a shallow copy of \a a to this array and returns a

    reference to this array.

    Equivalent to assign( a ).

*/

/*!

    \fn type *Q3MemArray::data() const

    Returns a pointer to the actual array data.

    The array is a null array if data() == 0 (null pointer).

    \sa isNull()

*/

/*!

    \fn uint Q3MemArray::nrefs() const

    Returns the reference count for the shared array data. This

    reference count is always greater than zero.

*/

/*!

    \fn uint Q3MemArray::size() const

    Returns the size of the array (maximum number of elements).

    The array is a null array if size() == 0.

    \sa isNull(), resize()

*/

/*!

    \fn uint Q3MemArray::count() const

    Returns the same as size().

    \sa size()

*/

/*!

    \fn bool Q3MemArray::isEmpty() const

    Returns TRUE if the array is empty; otherwise returns FALSE.

    isEmpty() is equivalent to isNull() for Q3MemArray (unlike

    QString).

*/

/*!

    \fn bool Q3MemArray::isNull() const

    Returns TRUE if the array is null; otherwise returns FALSE.

    A null array has size() == 0 and data() == 0.

*/

/*!

    \fn bool Q3MemArray::resize( uint size, Optimization optim )

    Resizes (expands or shrinks) the array to \a size elements. The

    array becomes a null array if \a size == 0.

    Returns TRUE if successful, or FALSE if the memory cannot be

    allocated.

    New elements are not initialized.

    \a optim is either Q3GArray::MemOptim (the default) or

    Q3GArray::SpeedOptim. When optimizing for speed rather than memory

    consumption, the array uses a smart grow and shrink algorithm that

    might allocate more memory than is actually needed for \a size

    elements. This speeds up subsequent resize operations, for example

    when appending many elements to an array, since the space has

    already been allocated.

    \sa size()

*/

/*!

    \fn bool Q3MemArray::resize( uint size )

    \overload

    Resizes (expands or shrinks) the array to \a size elements. The

    array becomes a null array if \a size == 0.

    Returns TRUE if successful, i.e. if the memory can be allocated;

    otherwise returns FALSE.

    New elements are not initialized.

    \sa size()

*/

/*!

    \fn bool Q3MemArray::truncate( uint pos )

    Truncates the array at position \a pos.

    Returns TRUE if successful, i.e. if the memory can be allocated;

    otherwise returns FALSE.

    Equivalent to resize(\a pos).

    \sa resize()

*/

/*!

    \fn bool Q3MemArray::fill( const type &v, int size )

    Fills the array with the value \a v. If \a size is specified as

    different from -1, then the array will be resized before being

    filled.

    Returns TRUE if successful, i.e. if \a size is -1, or \a size is

    != -1 and the memory can be allocated; otherwise returns FALSE.

    \sa resize()

*/

/*!

    \fn void Q3MemArray::detach()

    Detaches this array from shared array data; i.e. it makes a

    private, deep copy of the data.

    Copying will be performed only if the \link nrefs() reference

    count\endlink is greater than one.

    \sa copy()

*/

/*!

    \fn Q3MemArray<type> Q3MemArray::copy() const

    Returns a deep copy of this array.

    \sa detach(), duplicate()

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::assign( const Q3MemArray<type> &a )

    Shallow copy. Dereferences the current array and references the

    data contained in \a a instead. Returns a reference to this array.

    \sa operator=()

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::assign( const type *data, uint size )

    \overload

    Shallow copy. Dereferences the current array and references the

    array data \a data, which contains \a size elements. Returns a

    reference to this array.

    Do not delete \a data later; Q3MemArray will call free() on it

    at the right time.

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::duplicate( const Q3MemArray<type> &a )

    Deep copy. Dereferences the current array and obtains a copy of

    the data contained in \a a instead. Returns a reference to this

    array.

    \sa copy()

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::duplicate( const type *data, uint size )

    \overload

    Deep copy. Dereferences the current array and obtains a copy of

    the array data \a data instead. Returns a reference to this array.

    The size of the array is given by \a size.

    \sa copy()

*/

/*!

    \fn Q3MemArray<type> &Q3MemArray::setRawData( const type *data, uint size )

    Sets raw data and returns a reference to the array.

    Dereferences the current array and sets the new array data to \a

    data and the new array size to \a size. Do not attempt to resize

    or re-assign the array data when raw data has been set. Call

    resetRawData(\a data, \a size) to reset the array.

    Setting raw data is useful because it sets Q3MemArray data without

    allocating memory or copying data.

    Example I (intended use):

    \snippet doc/src/snippets/code/doc_src_q3memarray.qdoc 3

    Example II (you don't want to do this):

    \snippet doc/src/snippets/code/doc_src_q3memarray.qdoc 4

    \warning If you do not call resetRawData(), Q3MemArray will attempt

    to deallocate or reallocate the raw data, which might not be too

    good. Be careful.

    \sa resetRawData()

*/

/*!

    \fn void Q3MemArray::resetRawData( const type *data, uint size )

    Removes internal references to the raw data that was set using

    setRawData(). This means that Q3MemArray no longer has access to

    the \a data, so you are free to manipulate \a data as you wish.

    You can now use the Q3MemArray without affecting the original \a

    data, for example by calling setRawData() with a pointer to some

    other data.

    The arguments must be the \a data and length, \a size, that were

    passed to setRawData(). This is for consistency checking.

    \sa setRawData()

*/

/*!

    \fn int Q3MemArray::find( const type &v, uint index ) const

    Finds the first occurrence of \a v, starting at position \a index.

    Returns the position of \a v, or -1 if \a v could not be found.

    \sa contains()

*/

/*!

    \fn int Q3MemArray::contains( const type &v ) const

    Returns the number of times \a v occurs in the array.

    \sa find()

*/

/*!

    \fn void Q3MemArray::sort()

    Sorts the array elements in ascending order, using bitwise

    comparison (memcmp()).

    \sa bsearch()

*/

/*!

    \fn int Q3MemArray::bsearch( const type &v ) const

    In a sorted array (as sorted by sort()), finds the first

    occurrence of \a v by using a binary search. For a sorted

    array this is generally much faster than find(), which does

    a linear search.

    Returns the position of \a v, or -1 if \a v could not be found.

    \sa sort(), find()

*/

/*!

    \fn type &Q3MemArray::operator[]( int index ) const

    Returns a reference to the element at position \a index in the

    array.

    This can be used to both read and set an element. Equivalent to

    at().

    \sa at()

*/

/*!

    \fn type &Q3MemArray::at( uint index ) const

    Returns a reference to the element at position \a index in the array.

    This can be used to both read and set an element.

    \sa operator[]()

*/

/*!

    \fn Q3MemArray::operator const type *() const

    Cast operator. Returns a pointer to the array.

    \sa data()

*/

/*!

    \fn bool Q3MemArray::operator==( const Q3MemArray<type> &a ) const

    Returns TRUE if this array is equal to \a a; otherwise returns

    FALSE.

    The two arrays are compared bitwise.

    \sa operator!=()

*/

/*!

    \fn bool Q3MemArray::operator!=( const Q3MemArray<type> &a ) const

    Returns TRUE if this array is different from \a a; otherwise

    returns FALSE.

    The two arrays are compared bitwise.

    \sa operator==()

*/

/*!

    \fn Iterator Q3MemArray::begin()

    Returns an iterator pointing at the beginning of this array. This

    iterator can be used in the same way as the iterators of

    Q3ValueList and QMap, for example.

*/

/*!

    \fn Iterator Q3MemArray::end()

    Returns an iterator pointing behind the last element of this

    array. This iterator can be used in the same way as the iterators

    of Q3ValueList and QMap, for example.

*/

/*!

    \fn ConstIterator Q3MemArray::begin() const

    \overload

    Returns a const iterator pointing at the beginning of this array.

    This iterator can be used in the same way as the iterators of

    Q3ValueList and QMap, for example.

*/

/*!

    \fn ConstIterator Q3MemArray::end() const

    \overload

    Returns a const iterator pointing behind the last element of this

    array. This iterator can be used in the same way as the iterators

    of Q3ValueList and QMap, for example. 

*/