Wctypedigit

Wctypedigit is a term used in some wide-character processing contexts to denote the digit classification for wide characters. It refers to the set of characters that represent decimal digits, including ASCII digits as well as digits from other scripts when Unicode or locale data are in use. In this sense, wctypedigit is part of a broader scheme for classifying characters by type rather than by their visual shape alone.

In practice, wctypedigit can appear as either a predicate function or as a type mask within a locale-aware API. A predicate form would take a wide character and return true if it belongs to the digit category. A mask-based form would allow code to test membership via a standard wide-character classification function or macro. The essential behavior is to identify characters that are decimal digits according to the active locale or Unicode data, rather than just the ASCII range.

Unicode and locale considerations are central to wctypedigit. In Unicode terms, the digit property covers decimal digits across scripts, typically associated with the general category Nd. Implementations may expose wctypedigit as part of a broader wctype interface, alongside related categories such as alphabetic or alphanumeric. Developers use it for parsing numbers, input validation, and locale-aware digit handling in internationalized software.

See also: iswdigit, wctype, and locale-based character classification. Note that wctypedigit is a descriptive concept used in certain libraries and may not correspond to a single, standardized API across all platforms.