QPair Class

The QPair class is a template class that stores a pair of items. More...

Header: #include <QPair>
qmake: QT += core

Public Types

typedef first_type
typedef second_type

Public Functions

QPair()
QPair(const T1 & value1, const T2 & value2)
QPair(const QPair<TT1, TT2> & p)
QPair(QPair<TT1, TT2> && p)
void swap(QPair & other)
QPair & operator=(const QPair<TT1, TT2> & p)
QPair & operator=(QPair<TT1, TT2> && p)

Public Variables

T1 first
T2 second

Detailed Description

The QPair class is a template class that stores a pair of items.

QPair<T1, T2> can be used in your application if the STL pair type is not available. It stores one value of type T1 and one value of type T2. It can be used as a return value for a function that needs to return two values, or as the value type of a generic container.

Here's an example of a QPair that stores one QString and one double value:

QPair<QString, double> pair;

The components are accessible as public data members called first and second. For example:

pair.first = "pi";
pair.second = 3.14159265358979323846;

QPair's template data types (T1 and T2) must be assignable data types. You cannot, for example, store a QWidget as a value; instead, store a QWidget *. A few functions have additional requirements; these requirements are documented on a per-function basis.

See also Container Classes.

Member Type Documentation

typedef QPair::first_type

The type of the first element in the pair (T1).

See also first.

typedef QPair::second_type

The type of the second element in the pair (T2).

See also second.

Member Function Documentation

QPair::QPair()

Constructs an empty pair. The first and second elements are initialized with default-constructed values.

QPair::QPair(const T1 & value1, const T2 & value2)

Constructs a pair and initializes the first element with value1 and the second element with value2.

See also qMakePair().

QPair::QPair(const QPair<TT1, TT2> & p)

QPair::QPair(QPair<TT1, TT2> && p)

void QPair::swap(QPair & other)

QPair & QPair::operator=(const QPair<TT1, TT2> & p)

QPair & QPair::operator=(QPair<TT1, TT2> && p)

Member Variable Documentation

T1 QPair::first

The first element in the pair.

T2 QPair::second

The second element in the pair.