std::distance

 

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)

 

Biblioteca Iterator

Primitive iteratori Original: Iterator primitives The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
iterator_traits
input_iterator_tag output_iterator_tag forward_iterator_tag bidirectional_iterator_tag random_access_iterator_tag
iterator
Adattatori iteratori Original: Iterator adaptors The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
reverse_iterator
move_iterator (C++11) back_insert_iterator front_insert_iterator insert_iterator	make_move_iterator (C++11) back_inserter front_inserter inserter
Flusso iteratori Original: Stream iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
istream_iterator
ostream_iterator
istreambuf_iterator
ostreambuf_iterator
Operazioni di iteratori Original: Iterator operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
advance
distance
prev (C++11)
next (C++11)
Intervallo accesso Original: Range access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
begin (C++11)
end (C++11)

 

Defined in header <iterator>
template< class InputIt > typename std::iterator_traits<InputIt>::difference_type     distance( InputIt first, InputIt last );

Restituisce il numero di elementi tra first e last.

Original:

Returns the number of elements between first and last.

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Il comportamento è indefinito se last non è raggiungibile da first da (eventualmente più volte) l'incremento first.

Original:

The behavior is undefined if last is not reachable from first by (possibly repeatedly) incrementing first.

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Parametri

first	-	iteratore che punta al primo elemento Original: iterator pointing to the first element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
last	-	iteratore che punta all'ultimo elemento Original: iterator pointing to the last element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Type requirements
- InputIt must meet the requirements of InputIterator. The operation is more efficient if InputIt additionally meets the requirements of RandomAccessIterator

Valore di ritorno

Il numero di elementi tra first e last.

Original:

The number of elements between first and last.

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Complessità

Lineare.

Original:

Linear.

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Tuttavia, se InputIt soddisfa inoltre i requisiti di RandomAccessIterator, complessità è costante.

Original:

However, if InputIt additionally meets the requirements of RandomAccessIterator, complexity is constant.

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Esempio

#include <iostream>
#include <iterator>
#include <vector>
 
int main() 
{
    std::vector<int> v{ 3, 1, 4 };
 
    auto distance = std::distance(v.begin(), v.end());
 
    std::cout << distance << '\n';
}

Output:

3

Vedi anche

advance	avanza di un iteratore per distanza data Original: advances an iterator by given distance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione)