std::generate_n - cppreference.com

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Definido no cabeçalho `<algorithm>`

`template< class OutputIt, class Size, class Generator > void generate_n( OutputIt first, Size count, Generator g ); template< class OutputIt, class Size, class Generator > OutputIt generate_n( OutputIt first, Size count, Generator g );`		(até C++11) (desde C++11)

Atribui valores, gerados pela g dada função de objeto, para os elementos count primeira no início gama de first, se count>0. Não faz nada de outra forma.

Original:

Assigns values, generated by given function object g, to the first count elements in the range beginning at first, if count>0. Does nothing otherwise.

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Parâmetros

first	-	o início do intervalo de elementos para gerar Original: the beginning of the range of elements to generate The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
count	-	número de elementos de geração Original: number of the elements to generate The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
g	-	generator function object that will be called. The signature of the function should be equivalent to the following: <tbody> </tbody> The type `Ret` must be such that an object of type `OutputIt` can be dereferenced and assigned a value of type `Ret`.
Type requirements
-`OutputIt` must meet the requirements of `OutputIterator`.

Valor de retorno

(Nenhum) (até C++11)

Original:

(none) (até C++11)

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Iterator um passado o último elemento atribuído se count>0, first contrário. (desde C++11)

Original:

Iterator one past the last element assigned if count>0, first otherwise. (desde C++11)

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Complexidade

Exatamente count invocações de g() e atribuições, para count>0.

Original:

Exactly count invocations of g() and assignments, for count>0.

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Possível implementação

template< class OutputIt, class Size, class Generator >
OutputIt generate_n( OutputIt first, Size count, Generator g )
{
    for( Size i = 0; i < count; i++ ) {
        *first++ = g();
    }
    return first;
}

Exemplo

O código a seguir preenche um array de inteiros com números aleatórios .

Original:

The following code fills an array of integers with random numbers.

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#include <cstddef>
#include <cstdlib>
#include <iostream>
#include <iterator>
#include <algorithm>
 
int main()
{
    const std::size_t N = 5;
    int ar[N];
    std::generate_n(ar, N, std::rand); // Using the C function rand()
 
    std::cout << "ar: ";
    std::copy(ar, ar+N, std::ostream_iterator<int>(std::cout, " "));
    std::cout << "\n";
}

Saída:

52894 15984720 41513563 41346135 51451456

Veja também


	atribui um valor a um certo número de elementos Original: assigns a value to a number 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) [edit]

	guarda o resultado de uma função em um intervalo Original: saves the result of a function in a range 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) [edit]