std::for_each
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Definido no cabeçalho <algorithm> | ||
template<class InputIt, class UnaryFunction > UnaryFunction for_each( InputIt first, InputIt last, UnaryFunction f ); | ||
Aplica-se a
f determinado objeto função do resultado de cada dereferencing iterador na [first, last) gama, em ordem. Se InputIt é mutável iterador, f pode modificar os elementos da gama através do iterador dereferenced. Se f retorna um resultado, o resultado é ignorado.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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Índice |
[editar]Parâmetros
| first, last | - | a gama de aplicar a função de 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 | - | o objeto de função unária a ser aplicada 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. | ||
-UnaryFunction must meet the requirements of MoveConstructible. Does not have to be CopyConstructible | ||
[editar]Valor de retorno
f. (até C++11)
std::move(f). (desde C++11)
[editar]Complexidade
Exactamente
last - first aplicações de fOriginal:
Exactly
last - first applications of fThe text has been machine-translated via Google Translate.
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[editar]Possível implementação
template<class InputIt, class UnaryFunction> UnaryFunction for_each(InputIt first, InputIt last, UnaryFunction f){for(; first != last;++first){ f(*first);}return f;} |
[editar]Exemplo
O exemplo a seguir utiliza um função lambda para aumentar todos os elementos de um vector e, em seguida, calcula uma soma deles:
Original:
The following example uses a função 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';}
Saída:
before: 3 4 2 9 15 267 after: 4 5 3 10 16 268 sum: 306
[editar]Veja também
aplica-se uma função de uma série de elementos 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. (modelo de função) | |
| faixa para loop | executa loop sobre (desde C++11) alcance Original: executes loop over range (desde C++11) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
