The ISO standard 10646 is identical to the published Unicode standard and the CrossWorks C library uses the Unicode 6.0 definition as a base. Hence, whenever you see the term ‘Unicode’ in this document, it is equivalent to Unicode 6.0 and ISO/IEC 10646:2011.
The CrossWorks C library is compiled using a 32-bit wide character. The types wchar_t and wint_t are 32-bit integers that can hold any Unicode code point. Unicode only defines the code points 0 through 0x10FFFF with all others being undefined at this time.
The wide character type will hold Unicode code points in a locale that is defined to use Unicode and character type functions such as wisalpha will work correctly on all Unicode code points.