std::shared_ptr::use_count

<metanoindex/>

 

C++

Linguaggio

Concetti

Libreria di Utilità

Stringhe

Contenitori

Algoritmi

Iteratori

Libreria matematca

Input/output

Localizzazione

Espressioni regolari (C++11)

Operazioni atomicche (C++11)

Multithreading (C++11)

 

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)

 

Gestione della memoria dinamica

Basso livello di gestione della memoria
Allocatori Original: Allocators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
allocator
allocator_traits (C++11)
allocator_arg_t (C++11)
allocator_arg (C++11)
uses_allocator (C++11)
scoped_allocator_adaptor (C++11)
Non inizializzata stoccaggio Original: Uninitialized storage The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
uninitialized_copy
uninitialized_copy_n (C++11)
uninitialized_fill
uninitialized_fill_n
raw_storage_iterator
get_temporary_buffer
return_temporary_buffer
Puntatori intelligenti Original: Smart pointers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
unique_ptr (C++11)
shared_ptr (C++11)
weak_ptr (C++11)
auto_ptr (deprecato)
owner_less (C++11)
enable_shared_from_this (C++11)
bad_weak_ptr (C++11)
default_delete (C++11)
Garbage collection supporto Original: Garbage collection support The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
declare_reachable (C++11)
undeclare_reachable (C++11)
declare_no_pointers (C++11)
undeclare_no_pointers (C++11)
pointer_safety (C++11)
get_pointer_safety (C++11)
Varie Original: Miscellaneous The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
pointer_traits (C++11)
addressof (C++11)
align (C++11)
C Library Original: C Library The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
malloc calloc	realloc free

 

std::shared_ptr

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.

shared_ptr::shared_ptr

shared_ptr::~shared_ptr

shared_ptr::operator=

Modificatori Original: Modifiers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

shared_ptr::reset

shared_ptr::swap

Osservatori Original: Observers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

shared_ptr::get

shared_ptr::operator* shared_ptr::operator->

shared_ptr::use_count

shared_ptr::unique

shared_ptr::operator bool

shared_ptr::owner_before

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.

std::swap

make_shared

allocate_shared

static_pointer_cast dynamic_pointer_cast const_pointer_cast

get_deleter

operator== operator|= operator< operator<= operator> operator>=

operator<<

atomic_is_lock_free atomic_load atomic_load_explicit atomic_store atomic_store_explicit atomic_exchange atomic_exchange_explicit atomic_compare_exchange_weak atomic_compare_exchange_strong atomic_compare_exchange_weak_explicit atomic_compare_exchange_strong_explicit

std::hash

 

<tbody> </tbody>

long use_count() const;

Returns the number of different shared_ptr instances (this included) managing the current object. If there is no managed object, 0 is returned.

Parametri

(Nessuno)

Original:

(none)

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Valore di ritorno

the number of shared_ptr instances managing the current object or 0 if there is no managed object.

Esempio

#include <memory> 
#include <iostream> 
  
void fun(std::shared_ptr<int> sp)
{
    std::cout << "fun: sp.use_count() == " << sp.use_count() << std::endl; 
}

int main() 
{ 
    std::shared_ptr<int> sp1 {std::make_shared<int>(5)};
    std::cout << "sp1.use_count() == " << sp1.use_count() << std::endl; 

    fun(sp1);
}

Output:

sp1.use_count() == 1
fun: sp.use_count() == 2

Vedi anche

unique	Verifica se l'oggetto gestito è gestito solo dall'istanza shared_ptr corrente Original: checks whether the managed object is managed only by the current shared_ptr instance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)