From 7402070745824694845 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,a7bb6560624ae2c1 X-Google-Attributes: gidf78e5,public From: bruce.wheeler@siemens.at (Bruce Wheeler) Subject: Re: More M$ Not Conforming points... Date: 1999/08/25 Message-ID: <37c3beb7.9137699@news.sie.siemens.at>#1/1 X-Deja-AN: 517134801 Approved: Fergus Henderson References: <7ps1sg$dev$1@nnrp1.deja.com> <7pu4es$1mv3$1@news.hal-pc.org> X-Original-Date: Wed, 25 Aug 1999 10:22:10 GMT X-Complaints-To: news@news.unimelb.edu.au X-Trace: izvestia.its.unimelb.edu.au 935608056 4408 128.250.29.17 (25 Aug 1999 19:07:36 GMT) Organization: Siemens AG Austria X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBFAgUAN8Q+0uEDnX0m9pzZAQF55gGAnxAcMt+a0mRzvGDCC+EpJ2pCYTHPkY7B /XqjGgMSjCh3fmpxwmTNm9UMk1gOuc3c =V1fg NNTP-Posting-Date: 25 Aug 1999 19:07:36 GMT Newsgroups: comp.std.c++ On 24 Aug 99 20:53:22 GMT, "Greg Brewer" wrote: > wrote in message >news:7ps1sg$dev$1@nnrp1.deja.com... > >> Also, M$ will warn the developer if he/she does not return a value from >> main...which I can live with despite the fact that the C++ standard also >> states that main implicitly returns 0 if not specified. The problem is >> with their warning. Given the following: >> >> int main (void) { } >> VC++ produces the following warning: >> warning C4508: 'main' : function should return a value; 'void' return >> type assumed >> >> "void return type assumed" ???? What ? void assumed? > >This warning is no different than any other function without a return. I >think you will find that if you change it to > void main(void) {} >it will compile without any complaints. > >Greg Brewer This warning is quite different from all other functions without return values. See below (3.6.5). As commented by W.Bloodworth, VC++ is warning about well-defined legal C++. I don't know if it will return 0 as required by the standard, but it indicates that it will not (void type assumed). If you change it to void main(void) {}, as you suggest, you no longer have a valid ISO C++ program. (3.6.2 - It shall have a return type of type int). (from the C++ Standard) 3.6.1 Main function 1 A program shall contain a global function called main, which is the designated start of the program. It is implementation-defined whether a program in a freestanding environment is required to define a main function. ... 2 An implementation shall not predefine the main function. This func- tion shall not be overloaded. It shall have a return type of type int, but otherwise its type is implementation-defined. All implemen- tations shall allow both of the following definitions of main: int main() { /* ... */ } and int main(int argc, char* argv[]) { /* ... */ } ... 5 A return statement in main has the effect of leaving the main function (destroying any objects with automatic storage duration) and calling exit with the return value as the argument. If control reaches the end of main without encountering a return statement, the effect is that of executing return 0; Regards, Bruce Wheeler --- [ 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 ]