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📜  C++ STL-algorithm.move()函数

📅  最后修改于: 2020-10-16 09:13:40             🧑  作者: Mango

C++ STL algorithm函数move()

C++ STL algorithm.move()函数用于移动元素。它接受三个参数，然后将属于[first，last)范围的元素移动到以’result’开头的范围。

句法

template 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中。

last：它是范围中最后一个元素的输入迭代器，其中元素本身不包含在范围中。

结果：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已移动元素的序列。

例子1

#include      
#include     
#include       
#include        
#include        
int main () 
{
  std::vector a = {"suraj","aman","vanshika","chhavi"};
  std::vector 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
int main()
{
    std :: vector  u1 {9, 14, 21, 18};
    std :: vector  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

从第一个元素到最后一个元素，函数的复杂度是线性的。

数据竞争

访问某些或所有容器对象。

异常处理

如果任何容器元素抛出一个异常，该函数将引发异常。