/****************************************************************************
**
**
** QArray class documentation
**
** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
**
** This file is part of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
** information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/
/*****************************************************************************
QArray documentation
*****************************************************************************/
/*!
\class QArray qarray.h
\brief The QArray class is a template class that provides arrays of simple types.
\ingroup tools
QArray is implemented as a template class. Define a template
instance QArray\<X\> to create an array that contains X items.
QArray 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. QArray uses
bitwise operations to copy and compare array elements.
The QVector collection class is also a kind of array. Like most
\link collection.html collection classes\endlink, it has pointers to the
contained items.
QArray uses explicit \link shclass.html sharing\endlink with a reference
count. If more than one array share common data, and one array is
modified, all arrays will be modified.
The benefit of sharing is that a program does not need to duplicate
data when it is not required, which results in less memory usage and
less copying of data.
Example:
\code
#include <qarray.h>
#include <stdio.h>
QArray<int> fib( int num ) // returns fibonacci array
{
ASSERT( num > 2 );
QArray<int> f( num ); // array of ints
f[0] = f[1] = 1; // initialize first two numbers
for ( int i=2; i<num; i++ )
f[i] = f[i-1] + f[i-2];
return f;
}
void main()
{
QArray<int> a = fib( 6 ); // get 6 first fibonaccis
int i;
for ( i=0; i<a.size(); i++ ) // print them
prinf( "%d: %d\n", i, a[i] );
printf( "1 is found %d time(s)\n", a.contains(1) );
printf( "5 is found at index %d\n", a.find(5) );
}
\endcode
Program output:
\code
0: 1
1: 1
2: 2
3: 3
4: 5
5: 8
1 is found 2 times
5 is found at index 4
\endcode
Note about using QArray 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 QArray will use
for its bitwise element comparisons. Since the remaining bytes will
typically be uninitialized, this can cause find() etc. to fail to
find the element. Example:
\code
struct MyStruct
{
short i; // 2 bytes
char c; // 1 byte
}; // sizeof(MyStruct) may be padded to 4 bytes
QArray<MyStruct> a(1);
a[0].i = 5;
a[0].c = 't';
MyStruct x;
x.i = '5';
x.c = 't';
int i = a.find( x ); // May return -1 if the pad bytes differ
\endcode
To workaround 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.
\sa \link shclass.html Shared Classes\endlink
*/
/*!
\fn QArray::QArray()
Constructs a null array.
\sa isNull()
*/
/*!
\fn QArray::QArray( int size )
Constructs an array with room for \e size elements.
Makes a null array if \e size == 0.
Note that the elements are not initialized.
\sa resize(), isNull()
*/
/*!
\fn QArray::QArray( const QArray<type> &a )
Constructs a shallow copy of \e a.
\sa assign()
*/
/*!
\fn QArray::QArray( int, int )
Constructs an array <em>without allocating</em> array space.
The arguments should be (0, 0). Use at own risk.
*/
/*!
\fn QArray::~QArray()
Dereferences the array data and deletes it if this was the last
reference.
*/
/*!
\fn QArray<type> &QArray::operator=( const QArray<type> &a )
Assigns a shallow copy of \e a to this array and returns a reference
to this array.
Equivalent to assign( a ).
*/
/*!
\fn type *QArray::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 QArray::nrefs() const
Returns the reference count for the shared array data. This reference count
is always greater than zero.
*/
/*!
\fn uint QArray::size() const
Returns the size of the array (max number of elements).
The array is a null array if size() == 0.
\sa isNull(), resize()
*/
/*!
\fn uint QArray::count() const
Returns the same as size().
\sa size()
*/
/*!
\fn bool QArray::isEmpty() const
Returns TRUE if the array is empty, i.e. size() == 0, otherwise FALSE.
isEmpty() is equivalent with isNull() for QArray. Note that this is not
the case for QCString::isEmpty().
*/
/*!
\fn bool QArray::isNull() const
Returns TRUE if the array is null, otherwise FALSE.
A null array has size() == 0 and data() == 0.
*/
/*!
\fn bool QArray::resize( uint size )
Resizes (expands or shrinks) the array to \e size elements. The array
becomes a null array if \e size == 0.
Returns TRUE if successful, or FALSE if the memory cannot be allocated.
New elements will not be initialized.
\sa size()
*/
/*!
\fn bool QArray::truncate( uint pos )
Truncates the array at position \e pos.
Returns TRUE if successful, or FALSE if the memory cannot be allocated.
Equivalent to resize(\e pos).
\sa resize()
*/
/*!
\fn bool QArray::fill( const type &v, int size )
Fills the array with the value \e v. If \e size is specified as different
from -1, then the array will be resized before filled.
Returns TRUE if successful, or FALSE if the memory cannot be allocated
(only when \e size != -1).
\sa resize()
*/
/*!
\fn void QArray::detach()
Detaches this array from shared array data, i.e. makes a private, deep
copy of the data.
Copying will only be performed if the
\link nrefs() reference count\endlink is greater than one.
\sa copy()
*/
/*!
\fn QArray<type> QArray::copy() const
Returns a deep copy of this array.
\sa detach(), duplicate()
*/
/*!
\fn QArray<type> &QArray::assign( const QArray<type> &a )
Shallow copy. Dereferences the current array and references the data
contained in \e a instead. Returns a reference to this array.
\sa operator=()
*/
/*!
\fn QArray<type> &QArray::assign( const type *data, uint size )
Shallow copy. Dereferences the current array and references the
array data \e data, which contains \e size elements.
Returns a reference to this array.
Do not delete \e data later, QArray takes care of that.
*/
/*!
\fn QArray<type> &QArray::duplicate( const QArray<type> &a )
Deep copy. Dereferences the current array and obtains a copy of the data
contained in \e a instead. Returns a reference to this array.
\sa copy()
*/
/*!
\fn QArray<type> &QArray::duplicate( const type *data, uint size )
Deep copy. Dereferences the current array and obtains a copy of the
array data \e data instead. Returns a reference to this array.
\sa copy()
*/
/*!
\fn QArray<type> &QArray::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 \e data and
the new array size to \e size. Do not attempt to resize or re-assign the
array data when raw data has been set.
Call resetRawData(d,len) to reset the array.
Setting raw data is useful because it sets QArray data without allocating
memory or copying data.
Example I (intended use):
\code
static char bindata[] = { 231, 1, 44, ... };
QByteArray a;
a.setRawData( bindata, sizeof(bindata) ); // a points to bindata
QDataStream s( a, IO_ReadOnly ); // open on a's data
s >> <something>; // read raw bindata
a.resetRawData( bindata, sizeof(bindata) ); // finished
\endcode
Example II (you don't want to do this):
\code
static char bindata[] = { 231, 1, 44, ... };
QByteArray a, b;
a.setRawData( bindata, sizeof(bindata) ); // a points to bindata
a.resize( 8 ); // will crash
b = a; // will crash
a[2] = 123; // might crash
// forget to resetRawData - will crash
\endcode
\warning If you do not call resetRawData(), QArray will attempt to
deallocate or reallocate the raw data, which might not be too good.
Be careful.
\sa resetRawData()
*/
/*!
\fn void QArray::resetRawData( const type *data, uint size )
Resets raw data that was set using setRawData().
The arguments must be the data and length that were passed to
setRawData(). This is for consistency checking.
\sa setRawData()
*/
/*!
\fn int QArray::find( const type &v, uint index ) const
Finds the first occurrence of \e v, starting at position \e index.
Returns the position of \e v, or -1 if \e v could not be found.
\sa contains()
*/
/*!
\fn int QArray::contains( const type &v ) const
Returns the number of times \e v occurs in the array.
\sa find()
*/
/*!
\fn void QArray::sort()
Sorts the array elements in ascending order, using bitwise
comparison (memcmp()).
\sa bsearch()
*/
/*!
\fn int QArray::bsearch( const type &v ) const
In a sorted array, finds the first occurrence of \e v using binary
search. For a sorted array, this is generally much faster than
find(), which does a linear search.
Returns the position of \e v, or -1 if \e v could not be found.
\sa sort(), find()
*/
/*!
\fn type &QArray::operator[]( int index ) const
Returns a reference to the element at position \e index in the array.
This can be used to both read and set an element. Equivalent to at().
\sa at()
*/
/*!
\fn type &QArray::at( uint index ) const
Returns a reference to the element at position \e index in the array.
This can be used to both read and set an element.
\sa operator[]()
*/
/*!
\fn QArray::operator const type *() const
Cast operator. Returns a pointer to the array.
\sa data()
*/
/*!
\fn bool QArray::operator==( const QArray<type> &a ) const
Returns TRUE if this array is equal to \e a, otherwise FALSE.
The two arrays are bitwise compared.
\sa operator!=()
*/
/*!
\fn bool QArray::operator!=( const QArray<type> &a ) const
Returns TRUE if this array is different from \e a, otherwise FALSE.
The two arrays are bitwise compared.
\sa operator==()
*/
/*!
\fn Iterator QArray::begin()
Returns an iterator pointing at the beginning of this array.
This iterator can be used as the iterators of QValueList and QMap
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
*/
/*!
\fn Iterator QArray::end()
Returns an iterator pointing behind the last element of this array.
This iterator can be used as the iterators of QValueList and QMap
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
*/
/*!
\fn ConstIterator QArray::begin() const
Returns a const iterator pointing at the beginning of this array.
This iterator can be used as the iterators of QValueList and QMap
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
*/
/*!
\fn ConstIterator QArray::end() const
Returns a const iterator pointing behind the last element of this array.
This iterator can be used as the iterators of QValueList and QMap
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
*/
/*****************************************************************************
QByteArray documentation
*****************************************************************************/
/*!
\class QByteArray qcstring.h
\brief The QByteArray class provides an array of bytes.
\inherit QArray
\ingroup tools
The QByteArray class provides an explicitly shared array of
bytes. It is useful for manipulating memory areas with custom
data. QByteArray is implemented as QArray<char>. See the QArray
documentation for further information.
*/