QStack

QStack<T> is one of Qt's generic container classes. It implements a stack data structure for items of a same type.

A stack is a last in, first out (LIFO) structure. Items are added to the top of the stack using push() and retrieved from the top using pop(). The top() function provides access to the topmost item without removing it.

Example:

     QStack<int> stack;
     stack.push(1);
     stack.push(2);
     stack.push(3);
     while (!stack.isEmpty())
         cout << stack.pop() << endl;

The example will output 3, 2, 1 in that order.

QStack inherits from QVector. All of QVector's functionality also applies to QStack. For example, you can use isEmpty() to test whether the stack is empty, and you can traverse a QStack using QVector's iterator classes (for example, QVectorIterator). But in addition, QStack provides three convenience functions that make it easy to implement LIFO semantics: push(), pop(), and top().

QStack's value type must be an assignable data type. This covers most data types that are commonly used, but the compiler won't let you, for example, store a QWidget as a value; instead, store a QWidget *.