RtlLongToULongPtr - NtDoc

#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// LONG -> ULONG_PTR conversion
//
#ifdef _WIN64

_Must_inspect_result_
__inline
NTSTATUS
RtlLongToULongPtr(
    _In_ LONG lOperand,
    _Out_ _Deref_out_range_(==, lOperand) ULONG_PTR* pulResult)
{
    NTSTATUS status;
    
    if (lOperand >= 0)
    {
        *pulResult = (ULONG_PTR)lOperand;
        status = STATUS_SUCCESS;
    }
    else
    {
        *pulResult = ULONG_PTR_ERROR;
        status = STATUS_INTEGER_OVERFLOW;
    }
    
    return status;
}

#endif
#endif
#endif
View code on GitHub

#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// LONG -> ULONG_PTR conversion
//
#ifdef _WIN64
// ...
#else

#define RtlLongToULongPtr  RtlLongToULong

#endif
#endif
#endif
View code on GitHub