From -1813443419418561181 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,dfa6d585499f3572,start X-Google-Attributes: gidf78e5,public From: "Dave Abrahams" Subject: delete (T*)0; Date: 1999/06/21 Message-ID: #1/1 X-Deja-AN: 492295520 Content-Transfer-Encoding: 7bit Approved: Valentin Bonnard X-Original-Date: Sun, 20 Jun 1999 10:24:07 -0400 Content-Type: text/plain; charset="US-ASCII" Organization: Road Runner X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBVAwUAN27FeqwEuYhIxRhxAQFaSwIAhtkj68aHYGDA0ChWeoyrqe4C880jbNHj 3zXWY62ROGpkKlHWfWLZSuqLtuDFTUfyKNSO3QkhC/G/jbyCPlTnmQ== =RRFJ Mime-Version: 1.0 Newsgroups: comp.std.c++ I'm trying to find out whether, when calling delete on a null pointer value, the implementation is allowed to call operator delete anyway. I guess that it is legal for a function which is required to have "no effects" to call another function which has no effects, and operator delete is not allowed to have effects when called with a null pointer, so the answer is yes. Just how strongly is "no effect" indended? ---- 3.7.3.2 Deallocation functions [basic.stc.dynamic.deallocation] 3 The value of the first argument supplied to one of the deallocation functions provided in the standard library may be a null pointer value; if so, the call to the deallocation function has no effect. Otherwise, the value supplied to operator delete(void*) in the stan- dard library shall be one of the values returned by a previous invoca- tion of either operator new(size_t) or operator new(size_t, const std::nothrow_t&) in the standard library, and the value supplied to operator delete[](void*) in the standard library shall be one of the values returned by a previous invocation of either operator new[](size_t) or operator new[](size_t, const std::nothrow_t&) in the standard library. 5.3.5 Delete [expr.delete] 2 If the operand has a class type, the operand is converted to a pointer type by calling the above-mentioned conversion function, and the con- verted operand is used in place of the original operand for the remainder of this section. In either alternative, if the value of the operand of delete is the null pointer the operation has no effect... --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html ]