------- Additional Comments From falk at debian dot org 2005-07-14 21:47 ------- Subject: Re: pointer +- integer is never NULL
Gabriel Dos Reis <[EMAIL PROTECTED]> writes: > "falk at debian dot org" <[EMAIL PROTECTED]> writes: > > | ------- Additional Comments From falk at debian dot org 2005-07-14 15:37 > ------- > | (In reply to comment #7) > | > | > I'm failing to find anything in the C++ standard that suggests that the > | > following shall be undefined > | > > | > (reinterpret_cast<int*>(0) + 5) - 5 > | > | If (reinterpret_cast<int*>(0) + 5) - 5 is not undefined, then neither is > | reinterpret_cast<int*>(0) + 5. Then what is its result, by which paragraph > | in the standard? > > The standard says that the mapping used by reinterpret_cast to turn an > integer into a pointer is *implemented-defined*. It is not undefined. > GCC uses the "obvious" mapping, which is reinterpret_cast<int*>(0) is > the null pointer. So your example boils down further to the question of whether ((int*)0) + 5 is undefined, but you didn't answer my question yet. What is the result of ((int*)0) + 5, by which paragraph in the standard? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22485
