std::copy_n — cppreference.com
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| Déclaré dans l'en-tête <algorithm> |
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Copie exactement count valeurs du début de la plage à first au début de la plage à result, si count>0. Ne fait rien autrement .
Original:
Copies exactly count values from the range beginning at first to the range beginning at result, if count>0. Does nothing otherwise.
The text has been machine-translated via Google Translate.
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Paramètres
| first | - | le début de la série d'éléments à copier Original: the beginning of the range of elements to copy from The text has been machine-translated via Google Translate. |
| count | - | nombre d'éléments à copier Original: number of the elements to copy The text has been machine-translated via Google Translate. |
| result | - | le début de la plage de destination Original: the beginning of the destination range The text has been machine-translated via Google Translate. |
| Type requirements | ||
-InputIt must meet the requirements of InputIterator.
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-OutputIt must meet the requirements of OutputIterator.
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Retourne la valeur
Iterator dans la plage de destination, pointant après le dernier élément copié ou si count>0 first autrement .
Original:
Iterator in the destination range, pointing past the last element copied if count>0 or first otherwise.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Complexité
Exactement count missions, si count>0 .
Original:
Exactly count assignments, if count>0.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Mise en œuvre possible
template< class InputIt, class Size, class OutputIt> OutputIt copy_n(InputIt first, Size count, OutputIt result) { if (count > 0) { *result++ = *first; for (Size i = 1; i < count; ++i) { *result++ = *++first; } } return result; }
Exemple
#include <iostream> #include <string> #include <algorithm> #include <iterator> int main() { std::string in = "1234567890"; std::string out; std::copy_n(in.begin(), 4, std::back_inserter(out)); std::cout << out << '\n'; }
Résultat :
Voir aussi
Copie une série d'éléments vers un nouvel emplacement Original: copies a range of elements to a new location The text has been machine-translated via Google Translate. (fonction générique) [edit] | |