in phnt/include/ntwow64.h [577:585]
FORCEINLINE VOID UStr32ToUStr(
_Out_ PUNICODE_STRING Destination,
_In_ PUNICODE_STRING32 Source
)
{
Destination->Length = Source->Length;
Destination->MaximumLength = Source->MaximumLength;
Destination->Buffer = (PWCH)UlongToPtr(Source->Buffer);
}