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| 32 | <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QValueListIterator Class Reference</h1>
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| 33 |
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| 34 | <p>The QValueListIterator class provides an iterator for QValueList.
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| 35 | <a href="#details">More...</a>
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| 36 | <p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when Qt is built with thread support.</p>
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| 37 | <p><tt>#include <<a href="qvaluelist-h.html">qvaluelist.h</a>></tt>
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| 38 | <p><a href="qvaluelistiterator-members.html">List of all member functions.</a>
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| 39 | <h2>Public Members</h2>
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| 40 | <ul>
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| 41 | <li class=fn>typedef T <a href="#value_type"><b>value_type</b></a></li>
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| 42 | <li class=fn>typedef T * <a href="#pointer"><b>pointer</b></a></li>
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| 43 | <li class=fn>typedef T & <a href="#reference"><b>reference</b></a></li>
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| 44 | <li class=fn><a href="#QValueListIterator"><b>QValueListIterator</b></a> ()</li>
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| 45 | <li class=fn><a href="#QValueListIterator-3"><b>QValueListIterator</b></a> ( const QValueListIterator<T> & it )</li>
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| 46 | <li class=fn>bool <a href="#operator-eq-eq"><b>operator==</b></a> ( const QValueListIterator<T> & it ) const</li>
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| 47 | <li class=fn>bool <a href="#operator!-eq"><b>operator!=</b></a> ( const QValueListIterator<T> & it ) const</li>
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| 48 | <li class=fn>const T & <a href="#operator*-2"><b>operator*</b></a> () const</li>
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| 49 | <li class=fn>T & <a href="#operator*"><b>operator*</b></a> ()</li>
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| 50 | <li class=fn>QValueListIterator<T> & <a href="#operator++"><b>operator++</b></a> ()</li>
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| 51 | <li class=fn>QValueListIterator<T> <a href="#operator++-2"><b>operator++</b></a> ( int )</li>
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| 52 | <li class=fn>QValueListIterator<T> & <a href="#operator--"><b>operator--</b></a> ()</li>
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| 53 | <li class=fn>QValueListIterator<T> <a href="#operator---2"><b>operator--</b></a> ( int )</li>
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| 54 | <li class=fn>QValueListIterator<T> & <a href="#operator+-eq"><b>operator+=</b></a> ( int j )</li>
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| 55 | <li class=fn>QValueListIterator<T> & <a href="#operator--eq"><b>operator-=</b></a> ( int j )</li>
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| 56 | </ul>
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| 57 | <hr><a name="details"></a><h2>Detailed Description</h2>
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| 58 |
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| 59 |
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| 60 | The QValueListIterator class provides an iterator for <a href="qvaluelist.html">QValueList</a>.
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| 61 | <p>
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| 62 |
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| 63 |
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| 64 | <p> An iterator is a class for accessing the items of a container
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| 65 | class: a generalization of the index in an array. A pointer
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| 66 | into a "const char *" and an index into an "int[]" are both
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| 67 | iterators, and the general idea is to provide that functionality
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| 68 | for any data structure.
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| 69 | <p> The QValueListIterator class is an iterator for QValueList
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| 70 | instantiations. You can create the appropriate iterator type by
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| 71 | using the <tt>iterator</tt> typedef provided by QValueList.
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| 72 | <p> The only way to access the items in a QValueList is to use an
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| 73 | iterator.
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| 74 | <p> Example (see QValueList for the complete code):
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| 75 | <pre>
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| 76 | EmployeeList::iterator it;
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| 77 | for ( it = list.begin(); it != list.end(); ++it )
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| 78 | cout << (*it).surname().latin1() << ", " <<
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| 79 | (*it).forename().latin1() << " earns " <<
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| 80 | (*it).salary() << endl;
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| 81 |
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| 82 | // Output:
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| 83 | // Doe, John earns 50000
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| 84 | // Williams, Jane earns 80000
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| 85 | // Hawthorne, Mary earns 90000
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| 86 | // Jones, Tom earns 60000
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| 87 | </pre>
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| 88 |
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| 89 | <p> <a href="qvaluelist.html">QValueList</a> is highly optimized for performance and memory usage.
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| 90 | This means that you must be careful: QValueList does not know
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| 91 | about all its iterators and the iterators don't know to which list
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| 92 | they belong. This makes things very fast, but if you're not
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| 93 | careful, you can get spectacular bugs. Always make sure iterators
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| 94 | are valid before dereferencing them or using them as parameters to
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| 95 | generic algorithms in the STL or the <a href="qtl.html">QTL</a>.
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| 96 | <p> Using an invalid iterator is undefined (your application will
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| 97 | probably crash). Many Qt functions return const value lists; to
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| 98 | iterate over these you should make a copy and iterate over the
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| 99 | copy.
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| 100 | <p> For every Iterator there is a ConstIterator. When accessing a
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| 101 | QValueList in a const environment or if the reference or pointer
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| 102 | to the list is itself const, then you must use the ConstIterator.
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| 103 | Its semantics are the same as the Iterator, but it only returns
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| 104 | const references.
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| 105 | <p> <p>See also <a href="qvaluelist.html">QValueList</a>, <a href="qvaluelistconstiterator.html">QValueListConstIterator</a>, <a href="qtl.html">Qt Template Library Classes</a>, and <a href="tools.html">Non-GUI Classes</a>.
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| 106 |
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| 107 | <hr><h2>Member Type Documentation</h2>
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| 108 | <h3 class=fn><a name="pointer"></a>QValueListIterator::pointer</h3>
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| 109 | Pointer to value_type.
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| 110 | <h3 class=fn><a name="reference"></a>QValueListIterator::reference</h3>
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| 111 | Reference to value_type.
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| 112 | <h3 class=fn><a name="value_type"></a>QValueListIterator::value_type</h3>
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| 113 | The type of value, T.
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| 114 | <hr><h2>Member Function Documentation</h2>
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| 115 | <h3 class=fn><a name="QValueListIterator"></a>QValueListIterator::QValueListIterator ()
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| 116 | </h3>
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| 117 |
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| 118 | <p> Creates un uninitialized iterator.
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| 119 |
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| 120 | <h3 class=fn><a name="QValueListIterator-3"></a>QValueListIterator::QValueListIterator ( const <a href="qvaluelistiterator.html">QValueListIterator</a><T> & it )
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| 121 | </h3>
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| 122 |
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| 123 | <p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
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| 124 | <p> Constructs a copy of the iterator <em>it</em>.
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| 125 |
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| 126 | <h3 class=fn>bool <a name="operator!-eq"></a>QValueListIterator::operator!= ( const <a href="qvaluelistiterator.html">QValueListIterator</a><T> & it ) const
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| 127 | </h3>
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| 128 |
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| 129 | <p> Compares this iterator and <em>it</em> and returns TRUE if they point to
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| 130 | different items; otherwise returns FALSE.
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| 131 |
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| 132 | <h3 class=fn>T & <a name="operator*"></a>QValueListIterator::operator* ()
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| 133 | </h3>
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| 134 |
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| 135 | <p> Asterisk operator. Returns a reference to the current iterator item.
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| 136 |
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| 137 | <h3 class=fn>const T & <a name="operator*-2"></a>QValueListIterator::operator* () const
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| 138 | </h3>
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| 139 |
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| 140 | <p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
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| 141 | <p> Asterisk operator. Returns a reference to the current iterator item.
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| 142 |
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| 143 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> & <a name="operator++"></a>QValueListIterator::operator++ ()
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| 144 | </h3>
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| 145 |
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| 146 | <p> Prefix ++ makes the succeeding item current and returns an
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| 147 | iterator pointing to the new current item. The iterator cannot
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| 148 | check whether it reached the end of the list. Incrementing the
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| 149 | iterator returned by end() causes undefined results.
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| 150 |
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| 151 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> <a name="operator++-2"></a>QValueListIterator::operator++ ( int )
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| 152 | </h3>
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| 153 |
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| 154 | <p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
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| 155 | <p> Postfix ++ makes the succeeding item current and returns an
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| 156 | iterator pointing to the new current item. The iterator cannot
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| 157 | check whether it reached the end of the list. Incrementing the
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| 158 | iterator returned by end() causes undefined results.
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| 159 |
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| 160 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> & <a name="operator+-eq"></a>QValueListIterator::operator+= ( int j )
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| 161 | </h3>
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| 162 |
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| 163 | <p> Postfix -- jumps <em>j</em> steps forward in the list. The iterator
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| 164 | cannot check whether it reached the end of the list. Jumping past
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| 165 | the end() causes undefined results.
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| 166 |
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| 167 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> & <a name="operator--"></a>QValueListIterator::operator-- ()
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| 168 | </h3>
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| 169 |
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| 170 | <p> Prefix -- makes the previous item current and returns an iterator
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| 171 | pointing to the new current item. The iterator cannot check
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| 172 | whether it reached the beginning of the list. Decrementing the
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| 173 | iterator returned by begin() causes undefined results.
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| 174 |
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| 175 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> <a name="operator---2"></a>QValueListIterator::operator-- ( int )
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| 176 | </h3>
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| 177 |
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| 178 | <p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
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| 179 | <p> Postfix -- makes the previous item current and returns an iterator
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| 180 | pointing to the new current item. The iterator cannot check
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| 181 | whether it reached the beginning of the list. Decrementing the
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| 182 | iterator returned by begin() causes undefined results.
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| 183 |
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| 184 | <h3 class=fn><a href="qvaluelistiterator.html">QValueListIterator</a><T> & <a name="operator--eq"></a>QValueListIterator::operator-= ( int j )
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| 185 | </h3>
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| 186 |
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| 187 | <p> Postfix -- jumps <em>j</em> steps backward in the list. The iterator
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| 188 | cannot check whether it reached the beginning of the list. Jumping
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| 189 | past begin() causes undefined results.
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| 190 |
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| 191 | <h3 class=fn>bool <a name="operator-eq-eq"></a>QValueListIterator::operator== ( const <a href="qvaluelistiterator.html">QValueListIterator</a><T> & it ) const
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| 192 | </h3>
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| 193 |
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| 194 | <p> Compares this iterator and <em>it</em> and returns TRUE if they point to
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| 195 | the same item; otherwise returns FALSE.
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| 196 |
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| 197 | <!-- eof -->
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| 198 | <hr><p>
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| 199 | This file is part of the <a href="index.html">Qt toolkit</a>.
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| 200 | Copyright © 1995-2007
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| 201 | <a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
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| 202 | <table width=100% cellspacing=0 border=0><tr>
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| 203 | <td>Copyright © 2007
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| 204 | <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
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| 205 | <td align=right><div align=right>Qt 3.3.8</div>
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| 206 | </table></div></address></body>
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| 207 | </html>
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