Issue #9979: Create function PyUnicode_AsWideCharString().
diff --git a/Doc/c-api/unicode.rst b/Doc/c-api/unicode.rst
index 2e274ad..50a1254 100644
--- a/Doc/c-api/unicode.rst
+++ b/Doc/c-api/unicode.rst
@@ -462,6 +462,19 @@
    required by the application.
 
 
+.. cfunction:: wchar_t* PyUnicode_AsWideCharString(PyUnicodeObject *unicode, Py_ssize_t *size)
+
+   Convert the Unicode object to a wide character string. The output string
+   always ends with a nul character. If *size* is not *NULL*, write the number
+   of wide characters (including the nul character) into *\*size*.
+
+   Returns a buffer allocated by :cfunc:`PyMem_Alloc` (use :cfunc:`PyMem_Free`
+   to free it) on success. On error, returns *NULL*, *\*size* is undefined and
+   raises a :exc:`MemoryError`.
+
+   .. versionadded:: 3.2
+
+
 .. _builtincodecs:
 
 Built-in Codecs