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The QValueStack class is a value-based template class that provides a stack. More...
#include <qvaluestack.h>
Inherits QValueList<T>.
Defines a template instance QValueStack<X> to create a stack of values that all
have the class X. QValueStack is part of the .
Please note that QValueStack does not store pointers to the
members of the stack; it holds a copy of every member. That is why these
kinds of classes are called "value based"; QPtrStack, QPtrList, and QDict are "reference based".
A stack is a last in, first ut (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:
Program output:
Technically, QValueStack is a specialized QValueList provided for
convenience. All of QValueList's functionality applies also to
QPtrStack, for example the facility to iterate over all elements using
QValueStack Some classes cannot be used within a QValueStack, for example everything
derived from QObject and thus all classes that implement widgets.
Only values can be used in a QValueStack. To qualify as a value, the class
must provide
Note that C++ defaults to field-by-field assignment operators and
copy constructors if no explicit version is supplied. In many cases
this is sufficient.
Removes the top item from the stack and returns it.
See also top(), and and push().
Adds element, d, to the top of the stack. Last in, first out.
This function is equivalent to append().
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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#include <qvaluestack.h>
#include <stdio.h>
int main()
{
QValueStack<int> stack;
stack.push( 1 );
stack.push( 2 );
stack.push( 3 );
while ( !stack.isEmpty() )
printf("pop item %d\n", stack.pop() );
return 0;
}
pop item 3;
pop item 2;
pop item 1;
Member Function Documentation
QValueStack::QValueStack ()
Constructs an empty stack.
QValueStack::~QValueStack ()
Destroys the stack. References to the values in the stack and all iterators
of this stack become invalidated. Because QValueStack is highly tuned for performance,
you won't see warnings if you use invalid iterators
because it is impossible for an iterator to check whether or not it is valid.
T QValueStack::pop ()
void QValueStack::push ( const T & d )
T & QValueStack::top ()
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 points to.
const T & QValueStack::top () const
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
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