🚀 go-pugleaf

In article <49b202$62t@nntp.Stanford.EDU>, becker@Xenon.Stanford.EDU (Denizen of the Deep) writes:
>If the type (void *) is not compatible with pointer-to-function types,
>then why is the expression (void *)0 a legal null pointer constant?

Consider a different but equally logical question:
 If the type (int) is not compatible with pointer-to-function types,
 then why is the expression 0 a legal null pointer constant?

The answer to both questions is:  Because the standard says they are.
The standard defines this magic property for two kinds of expressions:
(1) any integral constant expression with value 0, and
(2) any integral constant expression with value 0 cast to type (void *).

An example of the first kind is:
 (int)0

Examples of the second kind are:
 (void *)0
 (void *)(int)0

A faulty example, which in fact is not a null pointer constant, is:
 (void *)(void *)0

An example which might or might not be, depending on the implementation
definition of NULL, is:
 (void *)NULL

>Since the null pointer constant is assignable to a pointer-to-function,
>it seems that this is rather misleading.

Since any null pointer constant is assignable to a pointer-to-function,
do you consider it misleading that 0 is a null pointer constant?
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