std::generate_n
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| Defined in header <algorithm>
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| template< class OutputIt, class Size, class Generator > void generate_n( OutputIt first, Size count, Generator g ); |
（至 C++11） （C++11 起） |
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受让人的值，所产生的给定的函数对象
g，开始的范围内，在第一count元素first，如果count>0。什么都不做，否则.....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.The text has been machine-translated via Google Translate.
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目录 |
[编辑] 参数
| first | - | 的范围内的元素，以产生的开始
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 | - | 的元素，以产生数目
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:
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.
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[编辑] 返回值
（无）（至 C++11）
Original:
(none) （至 C++11）
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如果
count>0，first否则分配的最后一个元素的迭代器一个过去。 （C++11 起）Original:
Iterator one past the last element assigned if
count>0, first otherwise. （C++11 起）The text has been machine-translated via Google Translate.
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[编辑] 复杂性
究竟
countg()调用和任务，count>0.Original:
Exactly
count invocations of g() and assignments, for count>0.The text has been machine-translated via Google Translate.
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[编辑] 可能的实现
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; } |
[编辑] 为例
下面的代码填充随机数的整数数组.
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"; }
Output:
52894 15984720 41513563 41346135 51451456
[编辑] 另请参阅
| 分配一个值，该值到的元素数 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. （函数模板） | |
| 并将结果保存在一个范围内的功能 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. （函数模板） | |
