/**************************************************************************** ** ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:FDL$ ** GNU Free Documentation License ** Alternatively, this file may be used under the terms of the GNU Free ** Documentation License version 1.3 as published by the Free Software ** Foundation and appearing in the file included in the packaging of ** this file. ** ** Other Usage ** Alternatively, this file may be used in accordance with the terms ** and conditions contained in a signed written agreement between you ** and Nokia. ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ /*! \class QPair \brief The QPair class is a template class that stores a pair of items. \ingroup tools QPair\ can be used in your application if the STL \c 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 \l{Container classes}{generic container}. Here's an example of a QPair that stores one QString and one \c double value: \snippet doc/src/snippets/code/doc_src_qpair.cpp 0 The components are accessible as public data members called \l first and \l second. For example: \snippet doc/src/snippets/code/doc_src_qpair.cpp 1 QPair's template data types (T1 and T2) must be \l{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. \sa {Container Classes} */ /*! \typedef QPair::first_type The type of the first element in the pair (T1). \sa first */ /*! \typedef QPair::second_type The type of the second element in the pair (T2). \sa second */ /*! \variable QPair::first The first element in the pair. */ /*! \variable QPair::second The second element in the pair. */ /*! \fn QPair::QPair() Constructs an empty pair. The \c first and \c second elements are initialized with \l{default-constructed values}. */ /*! \fn QPair::QPair(const T1 &value1, const T2 &value2) Constructs a pair and initializes the \c first element with \a value1 and the \c second element with \a value2. \sa qMakePair() */ /*! \fn QPair &QPair::operator=(const QPair &other) Assigns \a other to this pair. */ /*! \fn bool operator==(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is equal to \a p2; otherwise returns false. Two pairs compare equal if their \c first data members compare equal and if their \c second data members compare equal. This function requires the T1 and T2 types to have an implementation of \c operator==(). */ /*! \fn bool operator!=(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is not equal to \a p2; otherwise returns false. Two pairs compare as not equal if their \c first data members are not equal or if their \c second data members are not equal. This function requires the T1 and T2 types to have an implementation of \c operator==(). */ /*! \fn bool operator<(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is less than \a p2; otherwise returns false. The comparison is done on the \c first members of \a p1 and \a p2; if they compare equal, the \c second members are compared to break the tie. This function requires the T1 and T2 types to have an implementation of \c operator<(). */ /*! \fn bool operator>(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is greater than \a p2; otherwise returns false. The comparison is done on the \c first members of \a p1 and \a p2; if they compare equal, the \c second members are compared to break the tie. This function requires the T1 and T2 types to have an implementation of \c operator<(). */ /*! \fn bool operator<=(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is less than or equal to \a p2; otherwise returns false. The comparison is done on the \c first members of \a p1 and \a p2; if they compare equal, the \c second members are compared to break the tie. This function requires the T1 and T2 types to have an implementation of \c operator<(). */ /*! \fn bool operator>=(const QPair &p1, const QPair &p2) \relates QPair Returns true if \a p1 is greater than or equal to \a p2; otherwise returns false. The comparison is done on the \c first members of \a p1 and \a p2; if they compare equal, the \c second members are compared to break the tie. This function requires the T1 and T2 types to have an implementation of \c operator<(). */ /*! \fn QPair qMakePair(const T1 &value1, const T2 &value2) \relates QPair Returns a QPair\ that contains \a value1 and \a value2. Example: \snippet doc/src/snippets/code/doc_src_qpair.cpp 2 This is equivalent to QPair(\a value1, \a value2), but usually requires less typing. */ /*! \fn QDataStream &operator>>(QDataStream &in, QPair &pair) \relates QPair Reads a pair from stream \a in into \a pair. This function requires the T1 and T2 types to implement \c operator>>(). \sa {Serializing Qt Data Types} */ /*! \fn QDataStream &operator<<(QDataStream &out, const QPair &pair) \relates QPair Writes the pair \a pair to stream \a out. This function requires the T1 and T2 types to implement \c operator<<(). \sa {Serializing Qt Data Types} */