std::not2
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< cpp | utility | functional
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| Défini dans l'entête <functional>
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| template< class Predicate > std::binary_negate<Predicate> not2(const Predicate& pred); |
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not2 est une fonction d'assistance pour créer un objet fonction qui renvoie le complément de la fonction de prédicat binaire transmis. L'objet créé est fonction du type de std::binary_negate<Predicate> .Original:
not2 is a helper function to create a function object that returns the complement of the binary predicate function passed. The function object created is of type std::binary_negate<Predicate>.The text has been machine-translated via Google Translate.
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Le type de prédicat binaire devez définir deux types de membres,
first_argument_type et second_argument_type, qui sont convertibles à des types de paramètres de l'jacentes. Les objets obtenus à partir de la fonction std::owner_less, std::ref, std::cref, std::plus, std::minus, std::multiplies, std::divides, std::modulus, std::equal_to, std::not_equal_to, std::greater, std::less, std::greater_equal, std::less_equal, std::logical_not, std::logical_or, std::bit_and, std::bit_or, std::bit_xor, std::mem_fn, std::map::value_comp, std::multimap::value_comp, std::function , ou d'un autre appel à std::not2 avoir ces types définis, de même que les objets issus de la fonction std::binary_function obsolète . Original:
The binary predicate type must define two member types,
first_argument_type and second_argument_type, that are convertible to the predicate's parameter types. The function objects obtained from std::owner_less, std::ref, std::cref, std::plus, std::minus, std::multiplies, std::divides, std::modulus, std::equal_to, std::not_equal_to, std::greater, std::less, std::greater_equal, std::less_equal, std::logical_not, std::logical_or, std::bit_and, std::bit_or, std::bit_xor, std::mem_fn, std::map::value_comp, std::multimap::value_comp, std::function, or from another call to std::not2 have these types defined, as are function objects derived from the deprecated std::binary_function. The text has been machine-translated via Google Translate.
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Sommaire |
[modifier] Paramètres
| pred | - | prédicat unaire
Original: unary predicate The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[modifier] Retourne la valeur
std::not2 retourne un objet de std::binary_negate<Predicate> type, construits avec pred .Original:
The text has been machine-translated via Google Translate.
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[modifier] Exceptions
Aucun .
Original:
None.
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[modifier] Exemple
#include <algorithm> #include <functional> #include <iostream> #include <vector> struct old_same : std::binary_function<int, int, bool> { bool operator()(int a, int b) const { return a == b; } }; struct new_same { bool operator()(int a, int b) const { return a == b; } }; bool same_fn(int a, int b) { return a == b; } int main() { std::vector<int> v1{0, 1, 2}; std::vector<int> v2{2, 1, 0}; std::vector<bool> v3(v1.size()); std::cout << "negating a binary_function:\n"; std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), std::not2(old_same())); std::cout << std::boolalpha; for (std::size_t i = 0; i < v1.size(); ++i) std::cout << v1[i] << ' ' << v2[i] << ' ' << v3[i] << '\n'; std::cout << "negating a standard functor:\n"; std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), std::not2(std::equal_to<int>())); for (std::size_t i = 0; i < v1.size(); ++i) std::cout << v1[i] << ' ' << v2[i] << ' ' << v3[i] << '\n'; std::cout << "negating a std::function:\n"; std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), std::not2(std::function<bool(int,int)>(new_same()))); for (std::size_t i = 0; i < v1.size(); ++i) std::cout << v1[i] << ' ' << v2[i] << ' ' << v3[i] << '\n'; std::cout << "negating a std::reference_wrapper:\n"; std::transform(v1.begin(), v1.end(), v2.begin(), v3.begin(), std::not2(std::ref(same_fn))); for (std::size_t i = 0; i < v1.size(); ++i) std::cout << v1[i] << ' ' << v2[i] << ' ' << v3[i] << '\n'; }
Résultat :
negating a binary_function: 0 2 true 1 1 false 2 0 true negating a standard functor: 0 2 true 1 1 false 2 0 true negating a std::function: 0 2 true 1 1 false 2 0 true negating a std::reference_wrapper: 0 2 true 1 1 false 2 0 true
[modifier] Voir aussi
| foncteur retournant le complémentaire d'un foncteur existant, de type prédicat binaire (classe générique) | |
| (C++11) |
adaptateur générique de foncteur (classe générique) |
| fonction permettant de construire un objet de type std::unary_negate (fonction générique) | |
| (obsolète) |
crée un foncteur à partir d'une fonction (fonction générique) |
| (obsolète) |
classe de base pour définir des foncteurs à 2 paramètres (classe générique) |