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copy_n
Copies a specified number of elements
Key Facts
Gyroscopic Couple: The rate of change of angular momentum (= Moment of Inertia.
= Angular velocity
= Angular velocity of precession.
Blaise Pascal (1623-1662) was a French mathematician, physicist, inventor, writer and Catholic philosopher.
Leonhard Euler (1707-1783) was a pioneering Swiss mathematician and physicist.
Definition
The copy_n() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.Interface
#include <algorithm> template < class InputIterator, class Size, class OutputIterator > OutputIterator copy_n( InputIterator first, Size count, OutputIterator result );Parameters:
| Parameter | Description |
|---|---|
| first | An input iterator that indicates where to copy elements from |
| count | A signed or unsigned integer type specifying the number of elements to copy |
| result | An output iterator that indicates where to copy elements to |
Description
Copy_n copies elements from the range[first, first + n) to the range [result, result + n).Return Value
Returns an output iterator where elements have been copied to. It is the same as the returned value of the third parameter,result.References
Example:
Example - copy_n algorithm
Problem
This example of program illustrates the functionality of copy_n() algorithm.
Workings
#include <iostream> #include <string> #include <algorithm> #include <iterator> int main() { std::string in = "1234567890"; std::string out; std::copy_n(in.begin(), 4, std::back_inserter(out)); std::cout <<out <<'\n'; return 0; }
Solution
Output:
1234
References