Does there exist software with a negative integer zero as a value and/or a standard allowing such a value?
Note that this excludes ISO C despite the term “negative zero” for the integer types (up to C17), because this notion was used only for the representation (i.e. encoding), as implied by 6.2.6.2p2 and p3. Contrary to the floating-point signed zeros, there is only a single integer 0 as a value in C.
I’m asking this because the IEEE 754-2019 standard allows integer formats to have negative zeros: it defines “integer format: A format not defined in this standard that represents a subset of the integers and perhaps additional values representing infinities, NaNs, or negative zeros.” But since IEEE 754-2019 does not specify anything concerning integers, this does not count for this question (though this definition could mean that languages without integer types could use a floating-point type for IEEE 754 bindings of the convertToInteger* operations, where the destination is an integer type).