BlitzMax Long values, Lua, and C...

__declspec(dllexport) int64_t getalong() { return 20000000000L; }

ffi.cdef[[
int64_t getalong();
]]

local LV = ffi.C.getalong()
local result = LV + 1LL
print( "Type: " .. type( result ) )
print( "Result: " .. tostring( result ) )

int64_t bb_getalong();
__declspec(dllexport) int64_t getalong() { return bb_getalong(); }

Extern "C"
  Function getalong:Long()
End Extern

Function getalong:Long()
  Return 20000000000:Long
End Function

void bb_getalong(int64_t *);

Function getalong:Long() "C"
    Return 200000000000:Long
End Function

void bb_getindexlong( BBArray *array, int index, int64_t *val );
__declspec(dllexport) int64_t getindexlong( BBArray *array, int index ) {
  int64_t *v;
  bb_getindexlong( array, index, v );
  return *v;
}

Function getindexlong( array:Long[], index:Int, val:Long Var )
  val = array[index]
End Function

Function getindexlong( array:Long[], index:Int, val:Long Ptr )
  val[0] = array[index]
End Function

__declspec(dllexport) int64_t getindexlong( BBArray *array, int index ) {
  int64_t v;
  bb_getindexlong( array, index, &v );
  return v;
}

__declspec(dllexport) int64_t getindexlong( BBArray *array, int index ) {
  return ((int64_t *)BBARRAYDATA(array, array->dims))[index];
}