bits shared by the stringobject and unicodeobject implementations (and
possibly other modules, in a not too distant future).
the stuff in here is included into relevant places; see the individual
source files for details.
--------------------------------------------------------------------
the following defines used by the different modules:
STRINGLIB_CHAR
the type used to hold a character (char or Py_UNICODE)
STRINGLIB_EMPTY
a PyObject representing the empty string, only to be used if
STRINGLIB_MUTABLE is 0
Py_ssize_t STRINGLIB_LEN(PyObject*)
returns the length of the given string object (which must be of the
right type)
PyObject* STRINGLIB_NEW(STRINGLIB_CHAR*, Py_ssize_t)
creates a new string object
STRINGLIB_CHAR* STRINGLIB_STR(PyObject*)
returns the pointer to the character data for the given string
object (which must be of the right type)
int STRINGLIB_CHECK_EXACT(PyObject *)
returns true if the object is an instance of our type, not a subclass
STRINGLIB_MUTABLE
must be 0 or 1 to tell the cpp macros in stringlib code if the object
being operated on is mutable or not
