RtlStringCopyWorkerW - NtDoc

#ifndef _NTSTRSAFE_H_INCLUDED_

NTSTRSAFEWORKERDDI
RtlStringCopyWorkerW(
    _Out_writes_(cchDest) _Always_(_Post_z_) NTSTRSAFE_PWSTR pszDest,
    _In_ _In_range_(1, NTSTRSAFE_MAX_CCH) size_t cchDest,
    _Always_(_Out_opt_ _Deref_out_range_(<=, (cchToCopy < cchDest) ? cchToCopy : (cchDest - 1))) size_t* pcchNewDestLength,
    _In_reads_or_z_(cchToCopy) STRSAFE_PCNZWCH pszSrc,
    _In_ _In_range_(<, NTSTRSAFE_MAX_CCH) size_t cchToCopy);

#endif
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#ifndef _NTSTRSAFE_H_INCLUDED_
// Below here are the worker functions that actually do the work
#if defined(NTSTRSAFE_LIB_IMPL) || !defined(NTSTRSAFE_LIB)

NTSTRSAFEWORKERDDI
    RtlStringCopyWorkerW(
            _Out_writes_(cchDest) _Always_(_Post_z_) NTSTRSAFE_PWSTR pszDest,
            _In_ _In_range_(1, NTSTRSAFE_MAX_CCH) size_t cchDest,
            _Always_(_Out_opt_ _Deref_out_range_(<=, (cchToCopy < cchDest) ? cchToCopy : (cchDest - 1))) size_t* pcchNewDestLength,
            _In_reads_or_z_(cchToCopy) STRSAFE_PCNZWCH pszSrc,
            _In_ _In_range_(<, NTSTRSAFE_MAX_CCH) size_t cchToCopy)
{
    NTSTATUS status = STATUS_SUCCESS;
    size_t cchNewDestLength = 0;

    // ASSERT(cchDest != 0);

    while (cchDest && cchToCopy && (*pszSrc != L'\0'))
    {
        *pszDest++ = *pszSrc++;
        cchDest--;
        cchToCopy--;

        cchNewDestLength++;
    }

    if (cchDest == 0)
    {
        // we are going to truncate pszDest
        pszDest--;
        cchNewDestLength--;

        status = STATUS_BUFFER_OVERFLOW;
    }

    *pszDest = L'\0';

    if (pcchNewDestLength)
    {
        *pcchNewDestLength = cchNewDestLength;
    }

    return status;
}

#endif
#endif
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#ifndef _NTSTRSAFE_H_INCLUDED_
// Do not call these functions, they are worker functions for internal use within this file
#ifdef DEPRECATE_SUPPORTED
// ...
#else

#define RtlStringCopyWorkerW               RtlStringCopyWorkerW_instead_use_StringCchCopyW_or_StringCbCopyW

#endif
#endif
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