RtlLongToUInt8 - NtDoc

#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)

//
// LONG -> UINT8 conversion
//
_Must_inspect_result_
__inline
NTSTATUS
RtlLongToUInt8(
    _In_ LONG lOperand,
    _Out_ _Deref_out_range_(==, lOperand) UINT8* pui8Result)
{
    NTSTATUS status;
    
    if ((lOperand >= 0) && (lOperand <= UINT8_MAX))
    {
        *pui8Result = (UINT8)lOperand;
        status = STATUS_SUCCESS;
    }
    else
    {
        *pui8Result = UINT8_ERROR;
        status = STATUS_INTEGER_OVERFLOW;
    }
    
    return status;
}

#endif
#endif
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