std::pair::pair

Da cppreference.com.
< cpp‎ | utility‎ | pair

 
 
Utilità libreria
Tipo di supporto (basic types, RTTI, type traits)
Gestione della memoria dinamica
La gestione degli errori
Programma di utilità
Funzioni variadic
Data e ora
Funzione oggetti
initializer_list(C++11)
bitset
hash(C++11)
Gli operatori relazionali
Original:
Relational operators
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
Coppie e tuple
Original:
Pairs and tuples
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
pair
tuple(C++11)
piecewise_construct_t(C++11)
piecewise_construct(C++11)
Swap, in avanti e spostare
Original:
Swap, forward and move
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
swap
forward(C++11)
move(C++11)
move_if_noexcept(C++11)
declval(C++11)
 
std::pair
Membri funzioni
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
Non membri funzioni
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)
Helper classi
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)
 
pair();
constexpr pair();
(1) (fino al c++11)
(dal C++11)
pair(const T1& x, const T2& y );
(2)
template<class U1, class U2 >
pair( U1&& x, U2&& y );
(3) (dal C++11)
template<class U1, class U2 >
pair(const pair<U1,U2>& p );
(4)
template<class U1, class U2 >
pair( pair<U1,U2>&& p );
(5) (dal C++11)
template<class... Args1, class... Args2>

pair( std::piecewise_construct_t,
      std::tuple<Args1...> first_args,

      std::tuple<Args2...> second_args );
(6) (dal C++11)
pair(const pair& p )=default;
(7)
pair( pair&& p )=default;
(8) (dal C++11)


Costruisce una nuova coppia.
Original:
Constructs a new pair.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
1)
Costruttore di default. Valore-inizializza entrambi gli elementi della coppia, first e second.
Original:
Default constructor. Value-initializes both elements of the pair, first and second.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
2)
Inizializza first con x e second con y.
Original:
Initializes first with x and second with y.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
3)
Inizializza first con std::forward<U1>(x) e second con std::forward<U2>(y).
Original:
Initializes first with std::forward<U1>(x) and second with std::forward<U2>(y).
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
4)
Inizializza first con p.first e second con p.second.
Original:
Initializes first with p.first and second with p.second.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
5)
Inizializza first con std::move<U1>(p.first) e second con std::move<U2>(p.second).
Original:
Initializes first with std::move<U1>(p.first) and second with std::move<U2>(p.second).
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
6)
Contratti a termine gli elementi della first_args al costruttore di first e inoltra gli elementi della second_args al costruttore di second. Questo è l'unico costruttore non predefinito che può essere utilizzato per creare una coppia di non-copiabili non mobili tipi.
Original:
Forwards the elements of first_args to the constructor of first and forwards the elements of second_args to the constructor of second. This is the only non-default constructor that can be used to create a pair of non-copyable non-movable types.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
7)
Costruttore di copia è implicitamente generato.
Original:
Copy constructor is implicitly generated.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
8)
Costruttore Move è implicitamente generato.
Original:
Move constructor is implicitly generated.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifica]Parametri

x -
valore per inizializzare il primo elemento di questa coppia
Original:
value to initialize the first element of this pair
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
y -
valore per inizializzare il secondo elemento di questa coppia
Original:
value to initialize the second element of this pair
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
p -
coppia di valori utilizzati per inizializzare entrambi gli elementi di questa coppia
Original:
pair of values used to initialize both elements of this pair
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
first_args -
tupla di argomenti del costruttore per inizializzare il primo elemento di questa coppia
Original:
tuple of constructor arguments to initialize the first element of this pair
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
second_args -
tupla di argomenti del costruttore per inizializzare il secondo elemento di questa coppia
Original:
tuple of constructor arguments to initialize the second element of this pair
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifica]Esempio

#include <utility>#include <string>#include <complex>#include <tuple>#include <iostream>int main(){std::pair<int, float> p1;std::cout<<"Value-initialized: "<< p1.first<<", "<< p1.second<<'\n';   std::pair<int, double> p2(42, 0.123);std::cout<<"Initialized with two values: "<< p2.first<<", "<< p2.second<<'\n';   std::pair<char, int> p4(p2);std::cout<<"Implicitly converted: "<< p4.first<<", "<< p4.second<<'\n';   std::pair<std::complex<double>, std::string> p6( std::piecewise_construct, std::forward_as_tuple(0.123, 7.7), std::forward_as_tuple(10, 'a'));std::cout<<"Piecewise constructed: "<< p6.first<<", "<< p6.second<<'\n';}

Output:

Value-initialized: 0, 0 Initialized with two values: 42, 0.123 Implicitly converted: *, 0 Piecewise constructed: (0.123,7.7), aaaaaaaaaa

[modifica]Vedi anche

crea un oggetto di tipo pair, definita dai tipi di argomenti
Original:
creates a pair object of type, defined by the argument types
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(funzione di modello)[modifica]
close