You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
562 lines
27 KiB
562 lines
27 KiB
14 years ago
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
||
|
|
<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/qmemarray.doc:41 -->
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
|
||
|
|
<title>QMemArray Class</title>
|
||
|
|
<style type="text/css"><!--
|
||
|
|
fn { margin-left: 1cm; text-indent: -1cm; }
|
||
|
|
a:link { color: #004faf; text-decoration: none }
|
||
|
|
a:visited { color: #672967; text-decoration: none }
|
||
|
|
body { background: #ffffff; color: black; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
|
||
|
|
<table border="0" cellpadding="0" cellspacing="0" width="100%">
|
||
|
|
<tr bgcolor="#E5E5E5">
|
||
|
|
<td valign=center>
|
||
|
|
<a href="index.html">
|
||
|
|
<font color="#004faf">Home</font></a>
|
||
|
|
| <a href="classes.html">
|
||
|
|
<font color="#004faf">All Classes</font></a>
|
||
|
|
| <a href="mainclasses.html">
|
||
|
|
<font color="#004faf">Main Classes</font></a>
|
||
|
|
| <a href="annotated.html">
|
||
|
|
<font color="#004faf">Annotated</font></a>
|
||
|
|
| <a href="groups.html">
|
||
|
|
<font color="#004faf">Grouped Classes</font></a>
|
||
|
|
| <a href="functions.html">
|
||
|
|
<font color="#004faf">Functions</font></a>
|
||
|
|
</td>
|
||
|
|
<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QMemArray Class Reference</h1>
|
||
|
|
|
||
|
|
<p>The QMemArray class is a template class that provides arrays of simple types.
|
||
|
|
<a href="#details">More...</a>
|
||
|
|
<p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when Qt is built with thread support.</p>
|
||
|
|
<p><tt>#include <<a href="qmemarray-h.html">qmemarray.h</a>></tt>
|
||
|
|
<p>Inherited by <a href="qbytearray.html">QByteArray</a> and <a href="qpointarray.html">QPointArray</a>.
|
||
|
|
<p><a href="qmemarray-members.html">List of all member functions.</a>
|
||
|
|
<h2>Public Members</h2>
|
||
|
|
<ul>
|
||
|
|
<li class=fn>typedef type * <a href="#Iterator"><b>Iterator</b></a></li>
|
||
|
|
<li class=fn>typedef const type * <a href="#ConstIterator"><b>ConstIterator</b></a></li>
|
||
|
|
<li class=fn><a href="#QMemArray-2"><b>QMemArray</b></a> ()</li>
|
||
|
|
<li class=fn><a href="#QMemArray-3"><b>QMemArray</b></a> ( int size )</li>
|
||
|
|
<li class=fn><a href="#QMemArray-4"><b>QMemArray</b></a> ( const QMemArray<type> & a )</li>
|
||
|
|
<li class=fn><a href="#~QMemArray"><b>~QMemArray</b></a> ()</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#operator-eq"><b>operator=</b></a> ( const QMemArray<type> & a )</li>
|
||
|
|
<li class=fn>type * <a href="#data"><b>data</b></a> () const</li>
|
||
|
|
<li class=fn>uint <a href="#nrefs"><b>nrefs</b></a> () const</li>
|
||
|
|
<li class=fn>uint <a href="#size"><b>size</b></a> () const</li>
|
||
|
|
<li class=fn>uint <a href="#count"><b>count</b></a> () const</li>
|
||
|
|
<li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li>
|
||
|
|
<li class=fn>bool <a href="#isNull"><b>isNull</b></a> () const</li>
|
||
|
|
<li class=fn>bool <a href="#resize-2"><b>resize</b></a> ( uint size )</li>
|
||
|
|
<li class=fn>bool <a href="#resize"><b>resize</b></a> ( uint size, Optimization optim )</li>
|
||
|
|
<li class=fn>bool <a href="#truncate"><b>truncate</b></a> ( uint pos )</li>
|
||
|
|
<li class=fn>bool <a href="#fill"><b>fill</b></a> ( const type & v, int size = -1 )</li>
|
||
|
|
<li class=fn>virtual void <a href="#detach"><b>detach</b></a> ()</li>
|
||
|
|
<li class=fn>QMemArray<type> <a href="#copy"><b>copy</b></a> () const</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#assign"><b>assign</b></a> ( const QMemArray<type> & a )</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#assign-2"><b>assign</b></a> ( const type * data, uint size )</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#duplicate"><b>duplicate</b></a> ( const QMemArray<type> & a )</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#duplicate-2"><b>duplicate</b></a> ( const type * data, uint size )</li>
|
||
|
|
<li class=fn>QMemArray<type> & <a href="#setRawData"><b>setRawData</b></a> ( const type * data, uint size )</li>
|
||
|
|
<li class=fn>void <a href="#resetRawData"><b>resetRawData</b></a> ( const type * data, uint size )</li>
|
||
|
|
<li class=fn>int <a href="#find"><b>find</b></a> ( const type & v, uint index = 0 ) const</li>
|
||
|
|
<li class=fn>int <a href="#contains"><b>contains</b></a> ( const type & v ) const</li>
|
||
|
|
<li class=fn>void <a href="#sort"><b>sort</b></a> ()</li>
|
||
|
|
<li class=fn>int <a href="#bsearch"><b>bsearch</b></a> ( const type & v ) const</li>
|
||
|
|
<li class=fn>type & <a href="#operator[]"><b>operator[]</b></a> ( int index ) const</li>
|
||
|
|
<li class=fn>type & <a href="#at"><b>at</b></a> ( uint index ) const</li>
|
||
|
|
<li class=fn><a href="#operator-const-type-*"><b>operator const type *</b></a> () const</li>
|
||
|
|
<li class=fn>bool <a href="#operator-eq-eq"><b>operator==</b></a> ( const QMemArray<type> & a ) const</li>
|
||
|
|
<li class=fn>bool <a href="#operator!-eq"><b>operator!=</b></a> ( const QMemArray<type> & a ) const</li>
|
||
|
|
<li class=fn>Iterator <a href="#begin"><b>begin</b></a> ()</li>
|
||
|
|
<li class=fn>Iterator <a href="#end"><b>end</b></a> ()</li>
|
||
|
|
<li class=fn>ConstIterator <a href="#begin-2"><b>begin</b></a> () const</li>
|
||
|
|
<li class=fn>ConstIterator <a href="#end-2"><b>end</b></a> () const</li>
|
||
|
|
</ul>
|
||
|
|
<h2>Protected Members</h2>
|
||
|
|
<ul>
|
||
|
|
<li class=fn><a href="#QMemArray"><b>QMemArray</b></a> ( int, int )</li>
|
||
|
|
</ul>
|
||
|
|
<h2>Related Functions</h2>
|
||
|
|
<ul>
|
||
|
|
<li class=fn>Q_UINT16 <a href="#qChecksum"><b>qChecksum</b></a> ( const char * data, uint len )</li>
|
||
|
|
<li class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QByteArray & a )</li>
|
||
|
|
<li class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QByteArray & a )</li>
|
||
|
|
</ul>
|
||
|
|
<hr><a name="details"></a><h2>Detailed Description</h2>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
The QMemArray class is a template class that provides arrays of simple types.
|
||
|
|
<p>
|
||
|
|
<p> QMemArray is implemented as a template class. Define a template
|
||
|
|
instance QMemArray<X> to create an array that contains X items.
|
||
|
|
<p> QMemArray 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).
|
||
|
|
QMemArray uses bitwise operations to copy and compare array
|
||
|
|
elements.
|
||
|
|
<p> The <a href="qptrvector.html">QPtrVector</a> collection class is also a kind of array. Like most
|
||
|
|
<a href="collection.html">collection classes</a>, it uses pointers
|
||
|
|
to the contained items.
|
||
|
|
<p> QMemArray uses <a href="shclass.html">explicit sharing</a> with a
|
||
|
|
reference count. If more than one array shares common data and one
|
||
|
|
of the arrays is modified, all the arrays are modified.
|
||
|
|
<p> 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.
|
||
|
|
<p> An alternative to QMemArray is <a href="qvaluevector.html">QValueVector</a>. The QValueVector class
|
||
|
|
also provides an array of objects, but can deal with objects that
|
||
|
|
have constructors (specifically a copy constructor and a default
|
||
|
|
constructor). QValueVector provides an STL-compatible syntax and is
|
||
|
|
<a href="shclass.html">implicitly shared</a>.
|
||
|
|
<p> Example:
|
||
|
|
<pre>
|
||
|
|
#include <<a href="qmemarray-h.html">qmemarray.h</a>>
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
QMemArray<int> fib( int num ) // returns fibonacci array
|
||
|
|
{
|
||
|
|
<a href="qapplication.html#Q_ASSERT">Q_ASSERT</a>( num > 2 );
|
||
|
|
QMemArray<int> f( num ); // array of ints
|
||
|
|
|
||
|
|
f[0] = f[1] = 1;
|
||
|
|
for ( int i = 2; i < num; i++ )
|
||
|
|
f[i] = f[i-1] + f[i-2];
|
||
|
|
|
||
|
|
return f;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
QMemArray<int> a = fib( 6 ); // get first 6 fibonaccis
|
||
|
|
for ( int i = 0; i < a.<a href="#size">size</a>(); i++ )
|
||
|
|
<a href="qapplication.html#qDebug">qDebug</a>( "%d: %d", i, a[i] );
|
||
|
|
|
||
|
|
<a href="qapplication.html#qDebug">qDebug</a>( "1 is found %d times", a.<a href="#contains">contains</a>(1) );
|
||
|
|
<a href="qapplication.html#qDebug">qDebug</a>( "5 is found at index %d", a.<a href="#find">find</a>(5) );
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> Program output:
|
||
|
|
<pre>
|
||
|
|
0: 1
|
||
|
|
1: 1
|
||
|
|
2: 2
|
||
|
|
3: 3
|
||
|
|
4: 5
|
||
|
|
5: 8
|
||
|
|
1 is found 2 times
|
||
|
|
5 is found at index 4
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> Note concerning the use of QMemArray 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
|
||
|
|
QMemArray will use for its bitwise element comparisons. Because
|
||
|
|
the remaining bytes will typically be uninitialized, this can
|
||
|
|
cause <a href="#find">find</a>() etc. to fail to find the element. Example:
|
||
|
|
<p> <pre>
|
||
|
|
// MyStruct may be padded to 4 or 8 bytes
|
||
|
|
struct MyStruct
|
||
|
|
{
|
||
|
|
short i; // 2 bytes
|
||
|
|
char c; // 1 byte
|
||
|
|
};
|
||
|
|
|
||
|
|
QMemArray<MyStruct> a(1);
|
||
|
|
a[0].i = 5;
|
||
|
|
a[0].c = 't';
|
||
|
|
|
||
|
|
MyStruct x;
|
||
|
|
x.i = '5';
|
||
|
|
x.c = 't';
|
||
|
|
int i = a.<a href="#find">find</a>( x ); // may return -1 if the pad bytes differ
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> 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.
|
||
|
|
<p> QMemArray data can be traversed by iterators (see <a href="#begin">begin</a>() and
|
||
|
|
<a href="#end">end</a>()). The number of items is returned by <a href="#count">count</a>(). The array can
|
||
|
|
be resized with <a href="#resize">resize</a>() and filled using <a href="#fill">fill</a>().
|
||
|
|
<p> You can make a <a href="shclass.html#shallow-copy">shallow copy</a> of the array with <a href="#assign">assign</a>() (or
|
||
|
|
<a href="#operator-eq">operator=</a>()) and a <a href="shclass.html#deep-copy">deep copy</a> with <a href="#duplicate">duplicate</a>().
|
||
|
|
<p> Search for values in the array with <a href="#find">find</a>() and <a href="#contains">contains</a>(). For
|
||
|
|
sorted arrays (see <a href="#sort">sort</a>()) you can search using <a href="#bsearch">bsearch</a>().
|
||
|
|
<p> You can set the data directly using <a href="#setRawData">setRawData</a>() and
|
||
|
|
<a href="#resetRawData">resetRawData</a>(), although this requires care.
|
||
|
|
<p> <p>See also <a href="shclass.html">Shared Classes</a> and <a href="tools.html">Non-GUI Classes</a>.
|
||
|
|
|
||
|
|
<hr><h2>Member Type Documentation</h2>
|
||
|
|
<h3 class=fn><a name="ConstIterator"></a>QMemArray::ConstIterator</h3>
|
||
|
|
A const QMemArray iterator.
|
||
|
|
<p>See also <a href="#begin">begin</a>() and <a href="#end">end</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a name="Iterator"></a>QMemArray::Iterator</h3>
|
||
|
|
A QMemArray iterator.
|
||
|
|
<p>See also <a href="#begin">begin</a>() and <a href="#end">end</a>().
|
||
|
|
|
||
|
|
<hr><h2>Member Function Documentation</h2>
|
||
|
|
<h3 class=fn><a name="QMemArray"></a>QMemArray::QMemArray ( int, int )<tt> [protected]</tt>
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Constructs an array <em>without allocating</em> array space. The
|
||
|
|
arguments should be (0, 0). Use at your own risk.
|
||
|
|
|
||
|
|
<h3 class=fn><a name="QMemArray-2"></a>QMemArray::QMemArray ()
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Constructs a null array.
|
||
|
|
<p> <p>See also <a href="#isNull">isNull</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a name="QMemArray-3"></a>QMemArray::QMemArray ( int size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Constructs an array with room for <em>size</em> elements. Makes a null
|
||
|
|
array if <em>size</em> == 0.
|
||
|
|
<p> The elements are left uninitialized.
|
||
|
|
<p> <p>See also <a href="#resize">resize</a>() and <a href="#isNull">isNull</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a name="QMemArray-4"></a>QMemArray::QMemArray ( const <a href="qmemarray.html">QMemArray</a><type> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Constructs a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>a</em>.
|
||
|
|
<p> <p>See also <a href="#assign">assign</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a name="~QMemArray"></a>QMemArray::~QMemArray ()
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Dereferences the array data and deletes it if this was the last
|
||
|
|
reference.
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="assign"></a>QMemArray::assign ( const <a href="qmemarray.html">QMemArray</a><type> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> <a href="shclass.html#shallow-copy">Shallow copy</a>. Dereferences the current array and references the
|
||
|
|
data contained in <em>a</em> instead. Returns a reference to this array.
|
||
|
|
<p> <p>See also <a href="#operator-eq">operator=</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="assign-2"></a>QMemArray::assign ( const type * data, uint size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
|
||
|
|
<p> <a href="shclass.html#shallow-copy">Shallow copy</a>. Dereferences the current array and references the
|
||
|
|
array data <em>data</em>, which contains <em>size</em> elements. Returns a
|
||
|
|
reference to this array.
|
||
|
|
<p> Do not delete <em>data</em> later; QMemArray will call free() on it
|
||
|
|
at the right time.
|
||
|
|
|
||
|
|
<h3 class=fn>type & <a name="at"></a>QMemArray::at ( uint index ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns a reference to the element at position <em>index</em> in the array.
|
||
|
|
<p> This can be used to both read and set an element.
|
||
|
|
<p> <p>See also <a href="#operator[]">operator[]</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html#Iterator">Iterator</a> <a name="begin"></a>QMemArray::begin ()
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns an iterator pointing at the beginning of this array. This
|
||
|
|
iterator can be used in the same way as the iterators of
|
||
|
|
<a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>, for example.
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html#ConstIterator">ConstIterator</a> <a name="begin-2"></a>QMemArray::begin () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
|
||
|
|
<p> Returns a const iterator pointing at the beginning of this array.
|
||
|
|
This iterator can be used in the same way as the iterators of
|
||
|
|
<a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>, for example.
|
||
|
|
|
||
|
|
<h3 class=fn>int <a name="bsearch"></a>QMemArray::bsearch ( const type & v ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> In a sorted array (as sorted by <a href="#sort">sort</a>()), finds the first
|
||
|
|
occurrence of <em>v</em> by using a binary search. For a sorted
|
||
|
|
array this is generally much faster than <a href="#find">find</a>(), which does
|
||
|
|
a linear search.
|
||
|
|
<p> Returns the position of <em>v</em>, or -1 if <em>v</em> could not be found.
|
||
|
|
<p> <p>See also <a href="#sort">sort</a>() and <a href="#find">find</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>int <a name="contains"></a>QMemArray::contains ( const type & v ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns the number of times <em>v</em> occurs in the array.
|
||
|
|
<p> <p>See also <a href="#find">find</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> <a name="copy"></a>QMemArray::copy () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns a <a href="shclass.html#deep-copy">deep copy</a> of this array.
|
||
|
|
<p> <p>See also <a href="#detach">detach</a>() and <a href="#duplicate">duplicate</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>uint <a name="count"></a>QMemArray::count () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns the same as <a href="#size">size</a>().
|
||
|
|
<p> <p>See also <a href="#size">size</a>().
|
||
|
|
|
||
|
|
<p>Example: <a href="scribble-example.html#x913">scribble/scribble.cpp</a>.
|
||
|
|
<h3 class=fn>type * <a name="data"></a>QMemArray::data () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns a pointer to the actual array data.
|
||
|
|
<p> The array is a null array if <a href="#data">data</a>() == 0 (null pointer).
|
||
|
|
<p> <p>See also <a href="#isNull">isNull</a>().
|
||
|
|
|
||
|
|
<p>Examples: <a href="fileiconview-example.html#x855">fileiconview/qfileiconview.cpp</a> and <a href="networkprotocol-example.html#x671">network/networkprotocol/nntp.cpp</a>.
|
||
|
|
<h3 class=fn>void <a name="detach"></a>QMemArray::detach ()<tt> [virtual]</tt>
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Detaches this array from shared array data; i.e. it makes a
|
||
|
|
private, <a href="shclass.html#deep-copy">deep copy</a> of the data.
|
||
|
|
<p> Copying will be performed only if the <a href="#nrefs">reference
|
||
|
|
count</a> is greater than one.
|
||
|
|
<p> <p>See also <a href="#copy">copy</a>().
|
||
|
|
|
||
|
|
<p>Reimplemented in <a href="qbitarray.html#detach">QBitArray</a>.
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="duplicate"></a>QMemArray::duplicate ( const <a href="qmemarray.html">QMemArray</a><type> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> <a href="shclass.html#deep-copy">Deep copy</a>. Dereferences the current array and obtains a copy of
|
||
|
|
the data contained in <em>a</em> instead. Returns a reference to this
|
||
|
|
array.
|
||
|
|
<p> <p>See also <a href="#copy">copy</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="duplicate-2"></a>QMemArray::duplicate ( const type * data, uint size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
|
||
|
|
<p> <a href="shclass.html#deep-copy">Deep copy</a>. Dereferences the current array and obtains a copy of
|
||
|
|
the array data <em>data</em> instead. Returns a reference to this array.
|
||
|
|
The size of the array is given by <em>size</em>.
|
||
|
|
<p> <p>See also <a href="#copy">copy</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html#Iterator">Iterator</a> <a name="end"></a>QMemArray::end ()
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns an iterator pointing behind the last element of this
|
||
|
|
array. This iterator can be used in the same way as the iterators
|
||
|
|
of <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>, for example.
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html#ConstIterator">ConstIterator</a> <a name="end-2"></a>QMemArray::end () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
|
||
|
|
<p> 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 <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>, for example.
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="fill"></a>QMemArray::fill ( const type & v, int size = -1 )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Fills the array with the value <em>v</em>. If <em>size</em> is specified as
|
||
|
|
different from -1, then the array will be resized before being
|
||
|
|
filled.
|
||
|
|
<p> Returns TRUE if successful, i.e. if <em>size</em> is -1, or <em>size</em> is
|
||
|
|
!= -1 and the memory can be allocated; otherwise returns FALSE.
|
||
|
|
<p> <p>See also <a href="#resize">resize</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>int <a name="find"></a>QMemArray::find ( const type & v, uint index = 0 ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Finds the first occurrence of <em>v</em>, starting at position <em>index</em>.
|
||
|
|
<p> Returns the position of <em>v</em>, or -1 if <em>v</em> could not be found.
|
||
|
|
<p> <p>See also <a href="#contains">contains</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="isEmpty"></a>QMemArray::isEmpty () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns TRUE if the array is empty; otherwise returns FALSE.
|
||
|
|
<p> <a href="#isEmpty">isEmpty</a>() is equivalent to <a href="#isNull">isNull</a>() for QMemArray (unlike
|
||
|
|
<a href="qstring.html">QString</a>).
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="isNull"></a>QMemArray::isNull () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns TRUE if the array is null; otherwise returns FALSE.
|
||
|
|
<p> A null array has <a href="#size">size</a>() == 0 and <a href="#data">data</a>() == 0.
|
||
|
|
|
||
|
|
<h3 class=fn>uint <a name="nrefs"></a>QMemArray::nrefs () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns the reference count for the shared array data. This
|
||
|
|
reference count is always greater than zero.
|
||
|
|
|
||
|
|
<h3 class=fn><a name="operator-const-type-*"></a>QMemArray::operator const type * () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Cast operator. Returns a pointer to the array.
|
||
|
|
<p> <p>See also <a href="#data">data</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="operator!-eq"></a>QMemArray::operator!= ( const <a href="qmemarray.html">QMemArray</a><type> & a ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns TRUE if this array is different from <em>a</em>; otherwise
|
||
|
|
returns FALSE.
|
||
|
|
<p> The two arrays are compared bitwise.
|
||
|
|
<p> <p>See also <a href="#operator-eq-eq">operator==</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="operator-eq"></a>QMemArray::operator= ( const <a href="qmemarray.html">QMemArray</a><type> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Assigns a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>a</em> to this array and returns a
|
||
|
|
reference to this array.
|
||
|
|
<p> Equivalent to <a href="#assign">assign</a>( a ).
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="operator-eq-eq"></a>QMemArray::operator== ( const <a href="qmemarray.html">QMemArray</a><type> & a ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns TRUE if this array is equal to <em>a</em>; otherwise returns
|
||
|
|
FALSE.
|
||
|
|
<p> The two arrays are compared bitwise.
|
||
|
|
<p> <p>See also <a href="#operator!-eq">operator!=</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>type & <a name="operator[]"></a>QMemArray::operator[] ( int index ) const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns a reference to the element at position <em>index</em> in the
|
||
|
|
array.
|
||
|
|
<p> This can be used to both read and set an element. Equivalent to
|
||
|
|
<a href="#at">at</a>().
|
||
|
|
<p> <p>See also <a href="#at">at</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>void <a name="resetRawData"></a>QMemArray::resetRawData ( const type * data, uint size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Removes internal references to the raw data that was set using
|
||
|
|
<a href="#setRawData">setRawData</a>(). This means that QMemArray no longer has access to
|
||
|
|
the <em>data</em>, so you are free to manipulate <em>data</em> as you wish.
|
||
|
|
You can now use the QMemArray without affecting the original <em>data</em>, for example by calling setRawData() with a pointer to some
|
||
|
|
other data.
|
||
|
|
<p> The arguments must be the <em>data</em> and length, <em>size</em>, that were
|
||
|
|
passed to setRawData(). This is for consistency checking.
|
||
|
|
<p> <p>See also <a href="#setRawData">setRawData</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="resize"></a>QMemArray::resize ( uint size, Optimization optim )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Resizes (expands or shrinks) the array to <em>size</em> elements. The
|
||
|
|
array becomes a null array if <em>size</em> == 0.
|
||
|
|
<p> Returns TRUE if successful, or FALSE if the memory cannot be
|
||
|
|
allocated.
|
||
|
|
<p> New elements are not initialized.
|
||
|
|
<p> <em>optim</em> is either <tt>QGArray::MemOptim</tt> (the default) or
|
||
|
|
<tt>QGArray::SpeedOptim</tt>.
|
||
|
|
<p> <b>Note:</b> By default, <tt>SpeedOptim</tt> is not available for general
|
||
|
|
use since it is only available if Qt is built in a particular
|
||
|
|
configuration.
|
||
|
|
<p> <p>See also <a href="#size">size</a>().
|
||
|
|
|
||
|
|
<p>Example: <a href="fileiconview-example.html#x856">fileiconview/qfileiconview.cpp</a>.
|
||
|
|
<h3 class=fn>bool <a name="resize-2"></a>QMemArray::resize ( uint size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
|
||
|
|
<p> Resizes (expands or shrinks) the array to <em>size</em> elements. The
|
||
|
|
array becomes a null array if <em>size</em> == 0.
|
||
|
|
<p> Returns TRUE if successful, i.e. if the memory can be allocated;
|
||
|
|
otherwise returns FALSE.
|
||
|
|
<p> New elements are not initialized.
|
||
|
|
<p> <p>See also <a href="#size">size</a>().
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qmemarray.html">QMemArray</a><type> & <a name="setRawData"></a>QMemArray::setRawData ( const type * data, uint size )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Sets raw data and returns a reference to the array.
|
||
|
|
<p> Dereferences the current array and sets the new array data to <em>data</em> and the new array size to <em>size</em>. Do not attempt to resize
|
||
|
|
or re-assign the array data when raw data has been set. Call
|
||
|
|
<a href="#resetRawData">resetRawData</a>(<em>data</em>, <em>size</em>) to reset the array.
|
||
|
|
<p> Setting raw data is useful because it sets QMemArray data without
|
||
|
|
allocating memory or copying data.
|
||
|
|
<p> Example I (intended use):
|
||
|
|
<pre>
|
||
|
|
static char bindata[] = { 231, 1, 44, ... };
|
||
|
|
<a href="qbytearray.html">QByteArray</a> a;
|
||
|
|
a.<a href="#setRawData">setRawData</a>( bindata, sizeof(bindata) ); // a points to bindata
|
||
|
|
<a href="qdatastream.html">QDataStream</a> s( a, <a href="qfile.html#open">IO_ReadOnly</a> ); // open on a's data
|
||
|
|
s >> <something>; // read raw bindata
|
||
|
|
a.<a href="#resetRawData">resetRawData</a>( bindata, sizeof(bindata) ); // finished
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> Example II (you don't want to do this):
|
||
|
|
<pre>
|
||
|
|
static char bindata[] = { 231, 1, 44, ... };
|
||
|
|
<a href="qbytearray.html">QByteArray</a> a, b;
|
||
|
|
a.<a href="#setRawData">setRawData</a>( bindata, sizeof(bindata) ); // a points to bindata
|
||
|
|
a.<a href="#resize">resize</a>( 8 ); // will crash
|
||
|
|
b = a; // will crash
|
||
|
|
a[2] = 123; // might crash
|
||
|
|
// forget to resetRawData: will crash
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> <b>Warning:</b> If you do not call <a href="#resetRawData">resetRawData</a>(), QMemArray will attempt
|
||
|
|
to deallocate or reallocate the raw data, which might not be too
|
||
|
|
good. Be careful.
|
||
|
|
<p> <p>See also <a href="#resetRawData">resetRawData</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>uint <a name="size"></a>QMemArray::size () const
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns the size of the array (maximum number of elements).
|
||
|
|
<p> The array is a null array if <a href="#size">size</a>() == 0.
|
||
|
|
<p> <p>See also <a href="#isNull">isNull</a>() and <a href="#resize">resize</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>void <a name="sort"></a>QMemArray::sort ()
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Sorts the array elements in ascending order, using bitwise
|
||
|
|
comparison (memcmp()).
|
||
|
|
<p> <p>See also <a href="#bsearch">bsearch</a>().
|
||
|
|
|
||
|
|
<h3 class=fn>bool <a name="truncate"></a>QMemArray::truncate ( uint pos )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Truncates the array at position <em>pos</em>.
|
||
|
|
<p> Returns TRUE if successful, i.e. if the memory can be allocated;
|
||
|
|
otherwise returns FALSE.
|
||
|
|
<p> Equivalent to <a href="#resize">resize</a>(<em>pos</em>).
|
||
|
|
<p> <p>See also <a href="#resize">resize</a>().
|
||
|
|
|
||
|
|
<hr><h2>Related Functions</h2>
|
||
|
|
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-lt-lt"></a>operator<< ( <a href="qdatastream.html">QDataStream</a> & s, const <a href="qbytearray.html">QByteArray</a> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Writes byte array <em>a</em> to the stream <em>s</em> and returns a reference
|
||
|
|
to the stream.
|
||
|
|
<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
|
||
|
|
|
||
|
|
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-gt-gt"></a>operator>> ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qbytearray.html">QByteArray</a> & a )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Reads a byte array into <em>a</em> from the stream <em>s</em> and returns a
|
||
|
|
reference to the stream.
|
||
|
|
<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
|
||
|
|
|
||
|
|
<h3 class=fn>Q_UINT16 <a name="qChecksum"></a>qChecksum ( const char * data, uint len )
|
||
|
|
</h3>
|
||
|
|
|
||
|
|
<p> Returns the CRC-16 checksum of <em>len</em> bytes starting at <em>data</em>.
|
||
|
|
<p> The checksum is independent of the byte order (endianness).
|
||
|
|
|
||
|
|
<!-- eof -->
|
||
|
|
<hr><p>
|
||
|
|
This file is part of the <a href="index.html">Qt toolkit</a>.
|
||
|
|
Copyright © 1995-2007
|
||
|
|
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
|
||
|
|
<table width=100% cellspacing=0 border=0><tr>
|
||
|
|
<td>Copyright © 2007
|
||
|
|
<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
|
||
|
|
<td align=right><div align=right>Qt 3.3.8</div>
|
||
|
|
</table></div></address></body>
|
||
|
|
</html>
|