operator==,!=,<,<=,>,>=(std::pair)

 

C++

Langage

Concepts

Bibliothèque d'utilitaires

Bibliothèque pour les chaînes de caractères

Bibliothèque de conteneurs

Bibliothèque d'algorithmes

Bibliothèque d'itérateurs

Bibliothèque pour le calcul numérique

Bibliothèque pour les entrées/sorties

Bibliothèque pour la régionalisation

Bibliothèque pour les expressions régulières (C++11)

Bibliothèque pour les opérations atomiques (C++11)

Bibliothèque pour les processus légers (threads) (C++11)

 

Bibliothèque d'utilitaires

Soutien des types fondamentaux (basic types, RTTI, type traits)

Gestion dynamique de la mémoire

Gestion d'erreur

Soutien à l'exécution

Fonctions variadic

Date et heure

Foncteurs

initializer_list (C++11)

bitset

hash (C++11)

Opérateurs relationnels

rel_ops::operator!= rel_ops::operator> rel_ops::operator<= rel_ops::operator>=

Paires et tuples

pair

tuple (C++11)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

swap, forward et move

swap

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

declval (C++11)

 

std::pair

Les fonctions membres Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

pair::pair

pair::operator=

pair::swap

Tiers fonctions Original: Non-member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

make_pair

operator= operator!= operator< operator<= operator> operator>=

std::swap

get (C++11)

Classes d'aide Original: Helper classes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

tuple_size (C++11)

tuple_element (C++11)

 

Déclaré dans l'en-tête <utility>
template< class T1, class T2 > bool operator==( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(1)
template< class T1, class T2 > bool operator!=( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(2)
template< class T1, class T2 > bool operator<( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(3)
template< class T1, class T2 > bool operator<=( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(4)
template< class T1, class T2 > bool operator>( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(5)
template< class T1, class T2 > bool operator>=( const pair<T1,T2>& lhs, const pair<T1,T2>& rhs );	(6)

1-2)

Teste si deux éléments de lhs et rhs sont égaux, c'est-à-lhs.first compare avec rhs.first et lhs.second avec rhs.second

Original:

Tests if both elements of lhs and rhs are equal, that is, compares lhs.first with rhs.first and lhs.second with rhs.second

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3-6)

Compare lhs et rhs lexicographique, c'est-à-compare les premiers éléments et que si elles sont équivalentes, compare les deuxièmes éléments .

Original:

Compares lhs and rhs lexicographically, that is, compares the first elements and only if they are equivalent, compares the second elements.

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Paramètres

lhs, rhs

-

paires à comparer Original: pairs to compare The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Retourne la valeur

1)

true si les deux lhs.first == rhs.first et lhs.second == rhs.second, sinon false

Original:

true if both lhs.first == rhs.first and lhs.second == rhs.second, otherwise false

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2)

true si l'une ou lhs.first != rhs.first lhs.second != rhs.second, sinon false

Original:

true if either lhs.first != rhs.first or lhs.second != rhs.second, otherwise false

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3)

Si lhs.first<rhs.first, retourne true. Sinon, si rhs.first<lhs.first, retourne false. Sinon, si lhs.second<rhs.second, retourne true. Sinon, retourne false .

Original:

If lhs.first<rhs.first, returns true. Otherwise, if rhs.first<lhs.first, returns false. Otherwise, if lhs.second<rhs.second, returns true. Otherwise, returns false.

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4) !(rhs < lhs)

5) rhs < lhs

6) !(lhs < rhs)

Exemple

Parce que l'opérateur <est définie pour les couples, les conteneurs de paires peuvent être triés .

Original:

Because operator< is defined for pairs, containers of pairs can be sorted.

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#include <iostream>
#include <utility>
#include <vector>
#include <algorithm>
 
int main()
{
    std::vector<std::pair<int, std::string>> v = { {2, "baz"},
                                                   {2, "bar"},
                                                   {1, "foo"} };
    std::sort(v.begin(), v.end());
 
    for(auto p: v) {
        std::cout << "(" << p.first << "," << p.second << ")\n";
    }
}

Résultat :

(1,foo)
(2,bar)
(2,baz)