std::all_of, std::any_of, std::none_of — cppreference.com

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Déclaré dans l'en-tête `<algorithm>`
`template< class InputIt, class UnaryPredicate > bool all_of( InputIt first, InputIt last, UnaryPredicate p );`	(1)	(depuis C++11)
`template< class InputIt, class UnaryPredicate > bool any_of( InputIt first, InputIt last, UnaryPredicate p );`	(2)	(depuis C++11)
`template< class InputIt, class UnaryPredicate > bool none_of( InputIt first, InputIt last, UnaryPredicate p );`	(3)	(depuis C++11)

Vérifie si prédicat unaire p retours true pour tous les éléments de la gamme [first, last) .

Original:

Checks if unary predicate p returns true for all elements in the range [first, last).

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Vérifie si prédicat unaire p retours true pour au moins un élément dans la gamme [first, last) .

Original:

Checks if unary predicate p returns true for at least one element in the range [first, last).

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Vérifie si prédicat unaire p retours true pour aucun des éléments de la gamme [first, last) .

Original:

Checks if unary predicate p returns true for no elements in the range [first, last).

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Paramètres

first, last	-	l'éventail des éléments à examiner Original: the range of elements to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
p	-	prédicat unéaire . L'expression `p(v)` doit pouvoir être convertie à `bool` pour tout argument `v` de type (possiblement const) `VT`, où `VT` est le type de valeur de `InputIt`, inconditionellement de value category, et ne doit pas modifier `v`. Ainsi, un type-paramètre `VT&`n'est pas permis ainsi que pour `VT` sauf pour `VT` un déplacement est équivalent à une copie (depuis C++11).
Type requirements
-`InputIt` must meet the requirements of `InputIterator`.

Retourne la valeur

true si prédicat unaire renvoie true pour tous les éléments de la gamme, false autrement. Retours true si la plage est vide .

Original:

true if unary predicate returns true for all elements in the range, false otherwise. Returns true if the range is empty.

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true si prédicat unaire renvoie true pendant au moins un élément de la gamme, false autrement. Retours false si la plage est vide .

Original:

true if unary predicate returns true for at least one element in the range, false otherwise. Returns false if the range is empty.

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true si prédicat unaire renvoie true pour aucun des éléments de la gamme, false autrement. Retours true si la plage est vide .

Original:

true if unary predicate returns true for no elements in the range, false otherwise. Returns true if the range is empty.

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Complexité

Tout au plus last - first applications du prédicat

Original:

At most last - first applications of the predicate

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Mise en œuvre possible

First version
template< class InputIt, class UnaryPredicate > bool all_of(InputIt first, InputIt last, UnaryPredicate p) { for (; first != last; ++first) { if (!p(*first)) return false; } return true; }
Second version
template< class InputIt, class UnaryPredicate > bool any_of(InputIt first, InputIt last, UnaryPredicate p) { for (; first != last; ++first) { if (p(*first)) return true; } return false; }
Third version
template< class InputIt, class UnaryPredicate > bool none_of(InputIt first, InputIt last, UnaryPredicate p) { for (; first != last; ++first) { if (p(*first)) return false; } return true; }

Exemple

#include <vector>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <iostream>
#include <functional>
 
int main()
{
    std::vector<int> v(10, 2);
    std::partial_sum(v.cbegin(), v.cend(), v.begin());
    std::cout << "Among the numbers: ";
    std::copy(v.cbegin(), v.cend(), std::ostream_iterator<int>(std::cout, " "));
    std::cout << '\n';
 
    if (std::all_of(v.cbegin(), v.cend(), [](int i){ return i % 2 == 0; })) {
        std::cout << "All numbers are even\n";
    }
    if (std::none_of(v.cbegin(), v.cend(), std::bind(std::modulus<int>(), 
                                                     std::placeholders::_1, 2))) {
        std::cout << "None of them are odd\n";
    }
    struct DivisibleBy
    {
        const int d;
        DivisibleBy(int n) : d(n) {}
        bool operator()(int n) const { return n % d == 0; }
    };
 
    if (std::any_of(v.cbegin(), v.cend(), DivisibleBy(7))) {
        std::cout << "At least one number is divisible by 7\n";
    }
}

Résultat :

Among the numbers: 2 4 6 8 10 12 14 16 18 20 
All numbers are even
None of them are odd
At least one number is divisible by 7