C++ move()用法及代码示例

C++ 算法 move()function 用于移动元素。它接受三个参数，然后将属于范围 [first,last) 的元素移动到以 'result' 开头的范围中。

用法

template<class InputIterator, class OutputIterator> OutputIterator move(InputIterator first, InputIterator last, OutputIterator result);

参数

first:它是范围的第一个元素的输入迭代器，其中元素本身包含在范围内。

last: 它是范围最后一个元素的输入迭代器，其中元素本身不包含在范围内。

result:它是移动元素初始位置的输出迭代器。

返回值

该函数将第一个元素的迭代器返回到移动的元素序列。

例子1

#include <iostream>     
#include <algorithm>    
#include <utility>      
#include <vector>       
#include <string>       
int main () 
{
  std::vector<std::string> a = {"suraj","aman","vanshika","chhavi"};
  std::vector<std::string> b (4);
  std::cout << "Move function.\n";
  std::move ( a.begin(), a.begin()+4, b.begin() );
  std::cout << "a contains " << a.size() << " elements:";
  std::cout << " (The state of which is valid.)";
  std::cout << '\n';
  std::cout << "b contains " << b.size() << " elements:";
  for (std::string& x:b) std::cout << " [" << x << "]";
  std::cout << '\n';
  std::cout << "Moving the conatiner a...\n";
  a = std::move (b);
  std::cout << "a contains " << a.size() << " elements:";
  for (std::string& x:a) std::cout << " [" << x << "]";
  std::cout << '\n';
  std::cout << "b is in valid state";
  std::cout << '\n';
  return 0;
}

输出：

Move function.
a contains 4 elements:(The state of which is valid.)
b contains 4 elements:[suraj] [aman] [vanshika] [chhavi]
Moving the conatiner a...
a contains 4 elements:[suraj] [aman] [vanshika] [chhavi]
b is in valid state

例子2

#include<bits/stdc++.h>
int main()
{
	std::vector <int> u1 {9, 14, 21, 18};
	std::vector <int> u2 {14, 14, 14, 14};
	std::cout << "u1 contains:";
	for(int j = 0; j < u1.size(); j++)
		std::cout << " " << u1[j];
	std::cout << "\n";
	std::cout << "u2 contains:";
	for(unsigned int j = 0; j < u2.size(); j++)
		std::cout << " " << u2[j];
	std::cout << "\n\n";
	std::move (u1.begin(), u1.begin() + 4, u2.begin() + 1);
	std::cout << "u2 contains after move function:";
	for(unsigned int j = 0; j < u2.size(); j++)
		std::cout << " " << u2[j];
	std::cout << "\n";
	return 0;
}

输出：

u1 contains:9 14 21 18
u2 contains:14 14 14 14

u2 contains after move function:14 9 14 21

复杂度

函数的复杂度从第一个元素到最后一个元素是线性的。

数据竞争

访问部分或全部容器对象。

异常

如果任何容器元素抛出一个异常，该函数就会抛出异常。

相关用法

注：本文由纯净天空筛选整理自 C++ Algorithm Function move ()。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。