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[QtCore module]

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

#include <QPair>

- typedef
**first_type** - typedef
**second_type**

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 Generic Containers.

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

See also first.

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

See also second.

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

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

See also qMakePair().

Assigns *other* to this pair.

The first element in the pair.

The second element in the pair.

Returns a QPair<T1, T2> that contains *value1* and *value2*. Example:

QList<QPair<int, double> > list; list.append(qMakePair(66, 3.14159));

This is equivalent to QPair<T1, T2>(*value1*, *value2*), but usually requires less typing.

This is an overloaded member function, provided for convenience.

Returns true if *p1* is not equal to *p2*; otherwise returns false. Two pairs compare as not equal if their `first` data members are not equal or if their `second` data members are not equal.

This function requires the T1 and T2 types to have an implementation of `operator==()`.

Returns true if *p1* is less than *p2*; otherwise returns false. The comparison is done on the `first` members of *p1* and *p2*; if they compare equal, the `second` members are compared to break the tie.

This function requires the T1 and T2 types to have an implementation of `operator<()`.

This is an overloaded member function, provided for convenience.

Writes the pair *pair* to stream *out*.

This function requires the T1 and T2 types to implement `operator<<()`.

See also Format of the QDataStream operators.

Returns true if *p1* is less than or equal to *p2*; otherwise returns false. The comparison is done on the `first` members of *p1* and *p2*; if they compare equal, the `second` members are compared to break the tie.

This function requires the T1 and T2 types to have an implementation of `operator<()`.

This is an overloaded member function, provided for convenience.

Returns true if *p1* is equal to *p2*; otherwise returns false. Two pairs compare equal if their `first` data members compare equal and if their `second` data members compare equal.

This function requires the T1 and T2 types to have an implementation of `operator==()`.

Returns true if *p1* is greater than *p2*; otherwise returns false. The comparison is done on the `first` members of *p1* and *p2*; if they compare equal, the `second` members are compared to break the tie.

This function requires the T1 and T2 types to have an implementation of `operator<()`.

Returns true if *p1* is greater than or equal to *p2*; otherwise returns false. The comparison is done on the `first` members of *p1* and *p2*; if they compare equal, the `second` members are compared to break the tie.

This function requires the T1 and T2 types to have an implementation of `operator<()`.

This is an overloaded member function, provided for convenience.

Reads a pair from stream *in* into *pair*.

This function requires the T1 and T2 types to implement `operator>>()`.

See also Format of the QDataStream operators.

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