Hi folks!

I am playing around with a C library and came across
some issues related to unicode in C. In the unicode enabled
version of this C library which implements UCS-2 (i.e. just BMP)
the "unicode character type" is defined in the header file
as follows:
======================================
/*
* ZAB_CHAR
* ZAB_UC
*/

#ifdef ZABonAIX
#if defined(_AIX51) && defined(ZABwith64_BIT)
    #define ZABonAIX_wchar_is_4B
#else
    #define ZABonAIX_wchar_is_2B
#endif
#endif

#ifdef ZABonAIX
#if defined(_AIX51) && defined(ZABwith64_BIT)
    #define ZABonAIX_wchar_is_4B
#elif defined(ZABccQ)
    #define ZABonAIX_wchar_is_4B
#else
    #define ZABonAIX_wchar_is_2B
#endif
#endif

#if defined(ZABonNT)      || \
    defined(ZABonOS400)   || \
   (defined(ZABonOS390) && !defined(_LP64)) || \
    defined(ZABonAIX) && defined(ZABonAIX_wchar_is_2B)
#define WCHAR_is_2B
#else
#define WCHAR_is_4B
#endif

#if defined(ZABonLIN) && defined(GCC_UTF16_PATCH)
#if __GNUC_PREREQ (4,3)
    #include <uchar.h>
    #define ZAB_UC_is_char16
#endif
#endif

#ifndef ZABwithUNICODE
#define ZAB_UC_is_1B
typedef char ZAB_CHAR;
typedef char ZAB_UC;
#else /* ZABwithUNICODE */
#if defined(WCHAR_is_2B)
    #define ZAB_UC_is_wchar
    typedef wchar_t ZAB_CHAR;
    typedef wchar_t ZAB_UC;
#elif defined(ZAB_UC_is_char16)
    typedef char16_t ZAB_CHAR;
    typedef char16_t ZAB_UC;
#else
    #define ZAB_UC_is_UTF16_without_wchar
    typedef unsigned short ZAB_CHAR;
    typedef unsigned short ZAB_UC;
#endif
#endif /* ZABwithUNICODE or not */

/*
* CFRSDKwith(out)UTF16_LITERALS
* for CFR SDK applications: controls use of UTF-16
* literal enabled compilers.
*/
#if defined(CFRSDKwithUTF16_LITERALS)
#elif defined(CFRSDKwithoutUTF16_LITERALS)
#define ZABwithoutUTF16_LITERALS
#elif defined(WCHAR_is_2B) || \
    defined(ZABonHP_UX) || \
    (defined(ZABonLIN) && defined(__i386__) && defined(__GNUC__) && (__GNUC__<3)) || \
    (defined(ZABonLIN) && defined(GCC_UTF16_PATCH)) || \
    defined(ZABonSUN) || defined(ZABonAIX)
/* we have literals for UTF-16 */
#else
#define ZABwithoutUTF16_LITERALS
#endif
======================================

All this boils down to

+---------------------------+

+------>-| typedef wchar_t ZAB_CHAR; |

| | typedef wchar_t ZAB_UC; |

| +---------------------------+

+---------+ | +----------------------------+

| Unicode |------+------>-| typedef char16_t ZAB_CHAR; |

+---------+ | | typedef char16_t ZAB_UC; |

| +----------------------------+

| +----------------------------------+

+------>-| typedef unsigned short ZAB_CHAR; |

| typedef unsigned short ZAB_UC; |

+----------------------------------+

The question is now: Is it correct (resp. safe)
to defctype ZAB_UC just as :uint16 and interpret
it as a UFT-16 code point (with an appropriate endiannness)?

How can the types like wchar_t and char_16_t be defined (resp. used) in CFFI?

Regards
Nik