std::for_each
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<tbody> </tbody>| Dclar dans l'en-tte <algorithm>
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template< class InputIt, class UnaryFunction > UnaryFunction for_each( InputIt first, InputIt last, UnaryFunction f ); |
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Applique la fonction donne
f objet la suite de drfrencement chaque itration dans le [first, last) plage, dans l'ordre. Si InputIt est un itrateur modifiable, f peut modifier les lments de la gamme par l'itrateur drfrenc. Si f renvoie un rsultat, le rsultat est ignor .Original:
Applies the given function object
f to the result of dereferencing every iterator in the range [first, last), in order. If InputIt is a mutable iterator, f may modify the elements of the range through the dereferenced iterator. If f returns a result, the result is ignored.The text has been machine-translated via Google Translate.
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Paramtres
| first, last | - | la gamme d'appliquer la fonction d'
Original: the range to apply the function to The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| f | - | l'objet de fonction unaire appliqu
Original: the unary function object to be applied 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.
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-UnaryFunction must meet the requirements of MoveConstructible. Does not have to be CopyConstructible
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Retourne la valeur
f. (avant C++11)
std::move(f). (depuis C++11)
Complexit
Exactement
last - first applications de fOriginal:
Exactly
last - first applications of fThe text has been machine-translated via Google Translate.
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Mise en uvre possible
template<class InputIt, class UnaryFunction>
UnaryFunction for_each(InputIt first, InputIt last, UnaryFunction f)
{
for (; first != last; ++first) {
f(*first);
}
return f;
}
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Exemple
L'exemple suivant utilise une fonction lambda pour incrmenter tous les lments d'un vecteur, puis calcule une somme d'eux:
Original:
The following example uses a fonction lambda to increment all of the elements of a vector and then computes a sum of them:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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#include <vector>
#include <algorithm>
#include <iostream>
struct Sum {
Sum() { sum = 0; }
void operator()(int n) { sum += n; }
int sum;
};
int main()
{
std::vector<int> nums{3, 4, 2, 9, 15, 267};
std::cout << "before: ";
for (auto n : nums) {
std::cout << n << " ";
}
std::cout << '\n';
std::for_each(nums.begin(), nums.end(), [](int &n){ n++; });
Sum s = std::for_each(nums.begin(), nums.end(), Sum());
std::cout << "after: ";
for (auto n : nums) {
std::cout << n << " ";
}
std::cout << '\n';
std::cout << "sum: " << s.sum << '\n';
}
Rsultat :
before: 3 4 2 9 15 267
after: 4 5 3 10 16 268
sum: 306
Voir aussi
applique une fonction une srie d'lments Original: applies a function to a range of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction gnrique) | |
| de gamme pour la boucle | excute une boucle sur (depuis C++11) gamme
Original: executes loop over range (depuis C++11) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |