Why Doesn't C Automatically Set Pointers to NULL After Deletion?

Automatic Nullification Post-Deletion: Why Not?

The practice of automatically setting the pointer to NULL after performing a delete operation has been a topic of debate for programmers. Many argue that this measure would significantly reduce the occurrence of crashes caused by invalid pointers. However, the C standard has not adopted this approach, leaving users curious about the reasons behind this decision.

According to Bjarne Stroustrup, the creator of C , there are several factors that contributed to the exclusion of automatic pointer nullification:

Performance Considerations:

Introducing an additional instruction to zero out the pointer could impact the overall performance of delete operations, especially in scenarios where performance is critical.

Const Pointers:

Const pointers refer to memory locations that cannot be modified. Automatically setting such pointers to NULL could lead to undefined behavior, as modifying the contents of a const object is not permitted.

However, Stroustrup also acknowledged that these concerns could have been addressed through specialized handling of const pointers.

The standard allows delete operations on rvalues (temporary objects), which cannot be zeroed out. This technical limitation imposed by the language itself constitutes another obstacle to automatic pointer nullification.

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