Why is Using 'this' After 'delete this' in C a Bad Idea?

The Perils of "this" After "delete this"

The usage of the "delete this" construct in C is not without its pitfalls. While the first three restrictions on its use are understandable, the fourth restriction against examining its value or performing any other actions on it may seem perplexing. After all, it's just a pointer, right?

The reason for this seemingly arbitrary restriction lies in the undefined nature of the "this" pointer's value after calling "delete this." This undefined value can lead to unpredictable consequences and potentially catastrophic behavior.

For example, imagine reinterpreting the "this" pointer to an integer and then attempting to access it. The compiler is at liberty to decide that this action warrants wiping your hard drive. While most compilers would likely behave more reasonably, relying on their benignity in the face of undefined behavior is a hazardous game.

To avoid the risk of undefined behavior, it's prudent to make a copy of the pointer before deleting the object. This allows you to continue working with the copy while ensuring that the original "this" pointer's behavior remains predictably unpredictable.

The above is the detailed content of Why is Using 'this' After 'delete this' in C a Bad Idea?. For more information, please follow other related articles on the PHP Chinese website!