I don't want to get into this. I think enough has been said. I do want to avoid anyone misunderstanding what the ANSI/ISO Standards for C and C++ say about pow(0,0) however.
In general, C/C++ pow(0,0) is left implementation-defined. There may be a domain error (this is an implementation-defined result plus setting of a global condition). There may be a silent return of NaN. - Dennis DETAILS In ISO/IEC 14882-1998 (C++) the numeric_limits account for specializations in arithmetic that provide for +infinity and silent (non-exception-triggering) NaN among other cases. The value for *complex* pow(0,0) is implementation-defined in 26.2.8. For <cmath> (section 26.5) the definitions are deferred to the C Standard <math.h>, although more type specializations are provided for numtype pow(numtype1, numtype2). In ISO/IEC 14882-2003 (C++) is the same. I haven't checked -2011 and the standardization of some of the Boost library. In ISO/IEC 9899:2011 (C) the specification of cpow( ) does not say anything about cpow(0,0). The specification of pow(x,y) says that a domain error may occur if x is zero and y is zero. The same language appears in ISO C99 (including its Technical Corrigenda). In ANSI/ISO C (way back, before 1992) the rule was that "A domain error occurs if the result cannot be represented when x is zero and y is less than or equal to zero." (A domain error involves return of an implementation-defined value and the global error variable is set - exceptions aren't used in Standard C libraries.) So, considerable variability is provided. Quiet NaN and +Inf are representations, of course, if available in the library and arithmetic implementation. These are accounted for in 9899:2011. Plauger's "Standard C Library" (in 1992) assumes IEEE floating point and handles NaN and +Inf (and his implementation appears to return 1 for pow(0,0) -- the code is pretty snarly). -----Original Message----- From: Rob Weir [mailto:robw...@apache.org] Sent: Wednesday, February 20, 2013 07:08 To: dev@openoffice.apache.org Subject: Re: Solving this 0⁰ issue correctly (was Re: Calc behavior: result of 0 ^ 0) [ ... ] ANSI C, C99, ISO C++ all require that pow(x,0) return 1 for all values of x. [ ... ]
