Outlook add-in integrating Skype

#ifndef StringMgr_H
#define StringMgr_H

    #define INVALID_STRING_LENGTH   ((size_t)-1)

    typedef struct StringMgr StringMgr;
    struct StringMgr {
        size_t (NDAPI *Length)(
            StringMgr   *This,
            LPCWSTR     psz
            );
        BOOL (NDAPI *LengthEx)(
            StringMgr   *This,
            LPCWSTR     psz, 
            size_t      cchMax, 
            size_t      *pcchLength
            );
        BOOL (NDAPI *Copy)(
            StringMgr   *This,
            LPWSTR      Dst, 
            size_t      cch, 
            LPCWSTR     Src
            );
        BOOL (NDAPI *Dup)(
            StringMgr   *This,
            LPWSTR      *Dst, 
            LPCWSTR     Src
            );
        BOOL (NDAPI *Append)(
            StringMgr   *This,
            LPWSTR      Dst, 
            size_t      cch, 
            LPCWSTR     Src
            );
        BOOL (NDAPI *FormatV)(
            StringMgr   *This,
            LPWSTR      Dst, 
            size_t      cch, 
            LPCWSTR     Fmt, 
            va_list     ap 
            );
        BOOL (NDAPIV *Format)(
            StringMgr   *This,
            LPWSTR      Dst, 
            size_t      cch, 
            LPCWSTR     Fmt, 
            ...
            );
        LPWSTR (NDAPI *StrTok)(
            StringMgr   *This, 
            LPWSTR      psz, 
            LPCWSTR     separators
            );
    };

    StringMgr*
    StringMgr_GetObject(
        VOID
        );

    //  macros
    #define StringMgr_Length(This, psz) \
        ((This->Length)((This), (psz)))
    #define StringMgr_LengthEx(This, psz, cchMax, pcchLength) \
        ((This->LengthEx)((This), (psz), (cchMax), (pcchLength)))
    #define StringMgr_Copy(This, Dst, cch, Src) \
        ((This->Copy)((This), (Dst), (cch), (Src)))
    #define StringMgr_Dup(This, Dst, Src) \
        ((This->Dup)((This), (Dst), (Src)))
    #define StringMgr_Append(This, Dst, cch, Src) \
        ((This->Append)((This), (Dst), (cch), (Src)))
    #define StringMgr_StrTok(This, psz, sep) \
        ((This->StrTok)((This), (psz), (sep)))
    #define StringMgr_FormatV(This, psz, cch, fmt, ap) \
        (This->FormatV((This), (psz), (cch), (fmt), (ap)))
    #define StringMgr_Format0(This, psz, cch, fmt) \
        (This->Format((This), (psz), (cch), (fmt)))
    #define StringMgr_Format1(This, psz, cch, fmt, Arg1) \
        (This->Format((This), (psz), (cch), (fmt), (Arg1)))
    #define StringMgr_Format2(This, psz, cch, fmt, Arg1, Arg2) \
        (This->Format((This), (psz), (cch), (fmt), (Arg1), (Arg2)))
    #define StringMgr_Format3(This, psz, cch, fmt, Arg1, Arg2, Arg3) \
        (This->Format((This), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3)))
    #define StringMgr_Format4(This, psz, cch, fmt, Arg1, Arg2, Arg3, Arg4) \
        (This->Format((This), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3), (Arg4)))
    #define StringMgr_Format5(This, psz, cch, fmt, Arg1, Arg2, Arg3, Arg4, Arg5) \
        (This->Format((This), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3), (Arg4), (Arg5)))

    //  string copy into a static string
    #define SzStringLength(sz) \
        StringMgr_Length(StringMgr_GetObject(), (sz))
    #define SzStringLengthEx(psz, cch, pcch) \
        StringMgr_Length(StringMgr_GetObject(), (psz), (cch), (pcch))
    #define SzStringCopy(sz, Src) \
        StringMgr_Copy(StringMgr_GetObject(), (sz), (_countof(sz)), (Src))
    #define SzStringAppend(sz, Src) \
        StringMgr_Append(StringMgr_GetObject(), (sz), (_countof(sz)), (Src))
    #define SzStringFormatV(sz, fmt, ap) \
        StringMgr_FormatV(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (ap))
    #define SzStringStrTok(psz, sep) \
        StringMgr_StrTok(StringMgr_GetObject(), (psz), (sep))

    #define PszStringLength(psz) \
        StringMgr_Length(StringMgr_GetObject(), (psz))
    #define PszStringLengthEx(psz, cch, pcch) \
        StringMgr_LengthEx(StringMgr_GetObject(), (psz), (cch), (pcch))
    #define PszStringCopy(psz, cch, Src) \
        StringMgr_Copy(StringMgr_GetObject(), (psz), (cch), (Src))
    #define PszStringDup(Dst, Src) \
        StringMgr_Dup(StringMgr_GetObject(), (Dst), (Src))
    #define PszStringAppend(psz, cch, Src) \
        StringMgr_Append(StringMgr_GetObject(), (psz), (cch), (Src))
    #define PszStringFormatV(psz, cch, fmt, ap) \
        StringMgr_FormatV(StringMgr_GetObject(), (psz), (cch), (fmt), (ap))
    #define PszStringStrTok(psz, sep) \
        StringMgr_StrTok(StringMgr_GetObject(), (psz), (sep))

    //  _countof strings (locals)
    #define SzStringFormat0(sz, fmt) \
        StringMgr_Format0(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt))
    #define SzStringFormat1(sz, fmt, Arg1) \
        StringMgr_Format1(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (Arg1))
    #define SzStringFormat2(sz, fmt, Arg1, Arg2) \
        StringMgr_Format2(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (Arg1), (Arg2))
    #define SzStringFormat3(sz, fmt, Arg1, Arg2, Arg3) \
        StringMgr_Format3(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (Arg1), (Arg2), (Arg3))
    #define SzStringFormat4(sz, fmt, Arg1, Arg2, Arg3, Arg4) \
        StringMgr_Format4(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (Arg1), (Arg2), (Arg3), (Arg4))
    #define SzStringFormat5(sz, fmt, Arg1, Arg2, Arg3, Arg4, Arg5) \
        StringMgr_Format5(StringMgr_GetObject(), (sz), (_countof(sz)), (fmt), (Arg1), (Arg2), (Arg3), (Arg4), (Arg5))

    //  non-_countof strings (pointers)
    #define PszStringFormat0(psz, cch, fmt) \
        StringMgr_Format0(StringMgr_GetObject(), (psz), (cch), (fmt))
    #define PszStringFormat1(psz, cch, fmt, Arg1) \
        StringMgr_Format1(StringMgr_GetObject(), (psz), (cch), (fmt), (Arg1))
    #define PszStringFormat2(psz, cch, fmt, Arg1, Arg2) \
        StringMgr_Format2(StringMgr_GetObject(), (psz), (cch), (fmt), (Arg1), (Arg2))
    #define PszStringFormat3(psz, cch, fmt, Arg1, Arg2, Arg3) \
        StringMgr_Format3(StringMgr_GetObject(), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3))
    #define PszStringFormat4(psz, cch, fmt, Arg1, Arg2, Arg3, Arg4) \
        StringMgr_Format4(StringMgr_GetObject(), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3), (Arg4))
    #define PszStringFormat5(psz, cch, fmt, Arg1, Arg2, Arg3, Arg4, Arg5) \
        StringMgr_Format5(StringMgr_GetObject(), (psz), (cch), (fmt), (Arg1), (Arg2), (Arg3), (Arg4), (Arg5))

#endif  //  StringMgr_H