Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Keith Thompson Newsgroups: comp.lang.c Subject: Re: Integral types and own type definitions (was Re: Suggested method for returning a string from a C program?) Date: Tue, 25 Mar 2025 17:16:31 -0700 Organization: None to speak of Lines: 22 Message-ID: <87wmcc63z4.fsf@nosuchdomain.example.com> References: <868qp1ra5f.fsf@linuxsc.com> <20250319115550.0000676f@yahoo.com> <20250319201903.00005452@yahoo.com> <86r02roqdq.fsf@linuxsc.com> <86o6xpk8sn.fsf@linuxsc.com> <20250325011327.41@kylheku.com> <20250325131110.000056bd@yahoo.com> <87a5987sh8.fsf@nosuchdomain.example.com> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Wed, 26 Mar 2025 01:16:35 +0100 (CET) Injection-Info: dont-email.me; posting-host="469e8dc95fda8e96af14b48a4cec7ffc"; logging-data="450275"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX183KRskmI+7r3MT0GU+6knd" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:fEE6ytBfwu5AjLH78OMPPJWoiHE= sha1:6oJ7oPUC3UcZ0Bktiub/fkuDmGY= Bytes: 2694 James Kuyper writes: > On 3/25/25 16:41, Keith Thompson wrote: > ... >> Real numbers and floating-point numbers have different meanings, both in >> C and in general. > > One of the key differences is that all floating point numbers are > rational (except for the special values that mean various kinds of > infinity, and NaNs). Real numbers include the rational numbers and the > irrational ones. Just to confuse the point, some languages use "REAL" to > declare floating point variables. C defines a concept of "real types", which covers integer and floating types (and excludes complex and imaginary types -- BTW imaginary types are going away). C's real types are very different from mathematical real numbers; all C real non-special values are mathematical rational values. There are only finitely many values of real types in (any implementation of) C. -- Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com void Void(void) { Void(); } /* The recursive call of the void */