The QValueStack class is a value based template class that provides a stack. More...
#include <qvaluestack.h>
Inherits QValueList.
Define a template instance QValueStack<X> to create a stack of values which all have the class X. Please notice that QValueStack does not store pointers to the members of the stack. It holds a copy of every member. That is the reason why this kind of classes are called "value based" while QStack, QList and QDict are "reference based".
Some classes can not be used within a QValueStack. For example everything derived from QObject and as a reason of this that extends to all classes which implement widgets. You can only put stuff in a QValueStack which can be easily copied. That means that the class X should implement a fast copy constructor.
A stack is a Last In, First Out (LIFO) structure. Items are added to the top of the stack with push() and retrieved from the top with pop(). Furthermore, top() provides access to the topmost item without removing it.
Example:
#include <qvaluestack.h> #include <stdio.h> void main() { QValueStack<int> stack; stack.push( 1 ); stack.push( 2 ); stack.push( 3 ); while ( !stack.isEmpty() ) printf("pop item %d\n", stack.pop() ); }
Program output:
pop item 3; pop item 2; pop item 1;
Technically, QValueStack is a specialized QValueList provided for
convenience. All of QValueList's functionality applies also to
QStack, for example the facility to iterate over all elements using
QValueStack Constructs an empty stack.
Destroys the stack. References to the values in the stack and all iterators
of this stack become invalidated. Since QValueStack is highly tuned for performance
you wont see warnings if you use invalid iterators,
because it is impossible for an iterator to check wether it is valid or not.
Removes the top item from the stack and returns it.
Adds an element to the top of the stack. Last in, first out.
This function is equivalent to append()
Returns a reference to the top item of the stack or the item
referenced by end() if no
such item exists. Please note that you may not change
the value the end() Iterator is pointing to.
This function is equivalent to last().
See also: pop(), push() and QValueList::fromLast().
Returns a reference to the top item of the stack or the item
referenced by end() if no such item exists.
This function is equivalent to last().
See also: pop(), push() and QValueList::fromLast().
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Troll Tech, all rights reserved.Member Function Documentation
QValueStack::QValueStack ()
QValueStack::~QValueStack ()
T QValueStack::pop ()
void QValueStack::push ( const T & d )
T& QValueStack::top ()
const T& QValueStack::top () const
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