1 je to tam, kde se snazili redukovat "undefined behaviour", viz
https://en.wikipedia.org/wiki/Zero_to_the_power_of_zero#Programming_languages
The C and C++ standards do not specify the result of 0⁰ (a domain error may occur). But for C, as of C99, if the normative annex F is supported, the result for real floating-point types is required to be 1 because there are significant applications for which this value is more useful than NaN[28] (for instance, with discrete exponents); the result on complex types is not specified, even if the informative annex G is supported.