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nullptr pointer literal

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nullptr (C++11)
definito dall'utente (C++11)
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Indice

[modifica] Sintassi

nullptr (dal C++11)

[modifica] Spiegazione

Il nullptr parola chiave indica il puntatore nullo letterale. È un prvalue imprecisato di std::nullptr_t tipo. Esistono <div class="t-tr-text">conversioni implicite
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implicit conversions
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da nullptr al valore di puntatore nullo di qualsiasi tipo e di qualsiasi puntatore puntatore al tipo di membro. Conversioni simili esistono per ogni valore di std::nullptr_t tipo nonché per la NULL macro, il puntatore nullo costante.
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The keyword nullptr denotes the null pointer literal. It is an unspecified prvalue of type std::nullptr_t. There exist
conversioni implicite
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implicit conversions
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</div> from nullptr to null pointer value of any pointer type and any pointer to member type. Similar conversions exist for any value of type std::nullptr_t as well as for the macro NULL, the null pointer constant.
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[modifica] Esempio

Viene illustrato come nullptr consente l'inoltro tramite una funzione di modello .
Original:
Demonstrates how nullptr allows forwarding via a template function.
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#include <cstddef>
#include <iostream>
 
template<class F, class A>
void Fwd(F f, A a)
{
    f(a);
}
 
void g(int* i)
{
    std::cout << "Function g called\n";
}
 
int main()
{
    g(NULL);           // Fine
    g(0);              // Fine
 
    Fwd(g, nullptr);   // Fine
//  Fwd(g, NULL);  // ERROR: No function g(int)
}

Output: 

Function g called
Function g called
Function g called

[modifica] Parole chiave

nullptr

[modifica] Vedi anche
implementazione definita puntatore nullo costante
Original:
implementation-defined null pointer constant
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(macro costante) [modifica]
(C++11)
il tipo di puntatore nullo nullptr letterale
Original:
the type of the null pointer literal nullptr
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(typedef) [modifica]
Estratto da "https://it.cppreference.com/mwiki/index.php?title=cpp/language/nullptr&oldid=25967"