From 1263658867260726317 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,9a5d91576ea14293 X-Google-Attributes: gid109fba,public X-Google-Thread: f78e5,42ca30940288d269 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 1992-03-07 06:56:39 PST Xref: sparky comp.lang.c++:5632 comp.std.c++:281 Path: sparky!uunet!snorkelwacker.mit.edu!thunder.mcrcim.mcgill.edu!sobeco!philmtl!vedge!hendrik From: hendrik@vedge.UUCP (Hendrik Boom) Newsgroups: comp.lang.c++,comp.std.c++ Subject: Re: X to the Y power, how? Message-ID: <28541@vedge.UUCP> Date: 5 Mar 92 16:33:57 GMT References: <50175@hydra.gatech.EDU> <1992Feb27.135250.25403@ux1.cso.uiuc.edu> <1992Feb27.223558.276@rice.edu> <22292@alice.att.com> Reply-To: hendrik@vedge.UUCP (Hendrik Boom,,,) Organization: Visual Edge Software, St. Laurent, PQ Lines: 29 In article jbuck@forney.berkeley.edu (Joe Buck) writes: . Group 2: . long double operator@(long double,long int); . long double operator@(long double,unsigned int); . long double operator@(long double,int); . double operator@(double,long int); . double operator@(double,unsigned int); . double operator@(double,int); . float operator@(float,long int); . float operator@(float,unsigned int); . float operator@(float,int); . . is negative the result is undefined. For group 2 (floating base . raised to integral power), the first may be negative as long as . the second argument is zero or positive. If both arguments are . negative the result is undefined. For group 3, the result of a . negative second argument is undefined. You goofed on group 2; negative float to negative integer power is perfectly well-defined, and even returns a float. x * (- i) = 1/ ( x * i) as long as x is nonzero. By the way, 0 @ 0 is usually defined to be 1 when the zeros are integers; usually undefined when real or coimplex. -- Try one or more of the following addresses to reply. hendrik@vedge.uucp iros1!vedge!hendrik