Why Does a Void Pointer Assignment Work in C But Fail in C ?

Understanding the Void Pointer Differences Between C and C

In the realm of programming, understanding the differences between C and C is crucial, particularly when it comes to void pointers. A common question arises regarding why a particular C code compiles successfully but fails in C .

Assigning Void Pointers in C vs. C

The initial issue highlighted is the inability of C to assign the void pointer returned by malloc() to an integer pointer (int*). In C, however, such assignments are permitted due to its implicit conversions.

C 's Explicit Conversions with Void Pointers

In contrast to C, C enforces explicit conversions when assigning void pointers to other pointers. This means that a cast is required to convert a void pointer (void) to an integer pointer (int).

Conversion Rules and the K&R2 Principle

The K&R2 principle in C states that any pointer to an object can be converted to type void* without data loss. Similarly, converting this void pointer back to its original pointer type will preserve the original value.

C Standard on Void Pointer Conversions

Building upon the C principles, the C standard further dictates that conversions from T to void remain implicit. However, conversions from void* to any other pointer type must be explicitly cast.

In summary, while C allows implicit conversions to and from void pointers, C requires explicit casts for conversions from void* to other pointer types. This distinction ensures type safety and prevents potential errors in C code.

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