From 9154434319198383355 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,a5f5b2eff7f20a08 X-Google-Attributes: gid109fba,public X-Google-Thread: f78e5,8b7078226bb8aefc,start X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 1994-05-23 12:59:56 PST Newsgroups: comp.lang.c++,comp.std.c++ Path: bga.com!news.sprintlink.net!news.dorsai.org!news.ilx.com!psinntp!psinntp!ses.com!jamshid From: jamshid@ses.com (Jamshid Afshar) Subject: C vs C++ calling sequence (was Re: cast member funct ptr to pfn?) Message-ID: Followup-To: comp.std.c++ Sender: usenet@ses.com Nntp-Posting-Host: castro Organization: SES, Inc., Austin, TX, USA References: <2pp68l$a1d@sirius.cs.pdx.edu> Date: Mon, 23 May 1994 05:21:23 GMT Lines: 36 Xref: bga.com comp.lang.c++:16360 comp.std.c++:2422 Redirected to comp.std.c++. In article , James Kanze wrote: >In article jimad@microsoft.com (Jim Adcock) >writes: | >|> *Static* member functions can be cast to "C" function type, while allowing >|> you to keep the function name in the class namespace. > >For some implementations, as has been pointed out in another thread. >In particular, I would expect that good compilers for 80x86 will not >support this. (Typically, C functions will require the caller to do >stack clean-up, whereas C++ functions will have the callee do it.) I missed that thread, but there is no difference between ANSI C and C++ in this regard. It is illegal in ANSI C to call a function with a different number or type of arguments from the parameters declared in the function definition. ANSI C requires that functions taking variable arguments be prototyped before use using the ellipses notation. K&R1 didn't have the ellipses, function prototypes, or /, but it was hazy about the subject and stressed that there is no portable way to write a function taking a variable number of arguments: "printf, the most common C function with a variable number of arguments, [...] is also non-portable and must be modified for different environments". Point being, there's nothing stopping a C compiler vendor from using more efficient calling sequences or even type-safe linkage except their users who have a lot of broken code (at least in the eyes of ANSI C). Jamshid Afshar jamshid@ses.com