>> 1 Violation of any preconditions specified in a function’s Preconditions: element results in undefined behavior.
> ты такой остряк, в квн не пробовал выступать?
> специально для тебя разжую: что мешает ошибочно или специально разыменовать нулевой автоматический
> указатель?

Тебе ничего не мешает. Я могу это запретить - мне это разрешил стандарт:

3.30  [defns.undefined]  undefined behavior

behavior for which this document imposes no requirements

[Note 1 to entry: Undefined behavior may be expected when this document omits any explicit definition of
behavior or when a program uses an erroneous construct or erroneous data. Permissible undefined behavior
ranges from ignoring the situation completely with unpredictable results, to behaving during translation or
program execution in a documented manner characteristic of the environment (with or without the issuance
of a diagnostic message), to terminating a translation or execution (with the issuance of a diagnostic message).
Many erroneous program constructs do not engender undefined behavior; they are required to be diagnosed.
Evaluation of a constant expression never exhibits behavior explicitly specified as undefined in Clause 4
through Clause 15 of this document (7.7). — end note]