RtlUnicodeStringToCountedOemString

phnt::ffi

Function RtlUnicodeStringToCountedOemString 

Source 
pub unsafe extern "C" fn RtlUnicodeStringToCountedOemString(
    DestinationString: POEM_STRING,
    SourceString: PUNICODE_STRING,
    AllocateDestinationString: BOOLEAN,
) -> NTSTATUS