RtlULongLongToUIntPtr - NtDoc

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

_Must_inspect_result_
__inline
NTSTATUS
RtlULongLongToUIntPtr(
    _In_ ULONGLONG ullOperand,
    _Out_ _Deref_out_range_(==, ullOperand) UINT_PTR* puResult)
{
    *puResult = ullOperand;
    return STATUS_SUCCESS;
}

#endif
#endif
#endif
View code on GitHub

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

#define RtlULongLongToUIntPtr  RtlULongLongToUInt

#endif
#endif
#endif
View code on GitHub