C++ Destructor Applications

The main scenarios where a C++ destructor is used are:

1. Release dynamically allocated memory: When a class contains dynamically allocated memory (such as memory allocated using the new operator), it is necessary to release this memory when the object is destroyed. The destructor can be automatically called when the object is destroyed to release the memory and prevent memory leaks.
2. Closing files or releasing resources: When a class contains open files or other resources, it is necessary to close the files or release these resources when the object is destroyed. The destructor can automatically be called when the object is destroyed to perform the operation of closing files or releasing resources, thus avoiding resource leaks.
3. Cleaning up object states: When a class contains references to other objects or resources, it is necessary to perform clean-up operations when the object is destroyed, such as releasing references to other objects or breaking the relationships between objects.
4. Additional operations can be carried out: The destructor can perform tasks other than releasing memory, closing files, or releasing resources, such as logging information, sending messages, etc.

It is important to note that, in general, the destructor should only perform operations to release memory or resources, and should not carry out complex or time-consuming tasks in order to avoid impacting the program’s performance.