Implementing a noexcept move assignment operator

To implement a noexcept move assignment operator for a custom type, you need to define the operator= member function that takes an rvalue reference to the type and is marked as noexcept. Here's an example:

1#include <iostream>
2#include <utility>
3
4class MyType {
5 private:
6  int* data;
7
8 public:
9  MyType(int value) : data(new int(value)) {}
10
11  ~MyType() { delete data; }
12
13  MyType& operator=(MyType&& other) noexcept {  
14    if (this != &other) {
15      delete data;
16      data = other.data;
17      other.data = nullptr;
18    }
19    return *this;
20  }
21};
22
23int main() {
24  MyType obj1(10);
25  MyType obj2(20);
26
27  obj2 = std::move(obj1);
28}

In this example, the move assignment operator:

1. Checks for self-assignment to avoid deleting the object's own data.
2. Deletes the current object's data.
3. Moves the data pointer from the other object to the current object.
4. Sets the other object's data pointer to nullptr to avoid double deletion.
5. Returns a reference to the current object.

By marking the move assignment operator as noexcept, you indicate that it guarantees not to throw any exceptions, allowing it to be used in move operations without the risk of leaving objects in an indeterminate state.