Author: Armin Rigo <ar...@tunes.org>
Branch:
Changeset: r3013:7417b70e5b1a
Date: 2017-09-16 15:43 +0200
http://bitbucket.org/cffi/cffi/changeset/7417b70e5b1a/
Log: merge heads
diff --git a/doc/source/using.rst b/doc/source/using.rst
--- a/doc/source/using.rst
+++ b/doc/source/using.rst
@@ -128,10 +128,37 @@
There is no general equivalent to the ``&`` operator in C (because it
would not fit nicely in the model, and it does not seem to be needed
-here). But see `ffi.addressof()`__.
+here). There is `ffi.addressof()`__, but only for some cases. You
+cannot take the "address" of a number in Python, for example; similarly,
+you cannot take the address of a CFFI pointer. If you have this kind
+of C code::
+
+ int x, y;
+ fetch_size(&x, &y);
+
+ opaque_t *handle; // some opaque pointer
+ init_stuff(&handle); // initializes the variable 'handle'
+ more_stuff(handle); // pass the handle around to more functions
+
+then you need to rewrite it like this, replacing the variables in C
+with what is logically pointers to the variables:
+
+.. code-block:: python
+
+ px = ffi.new("int *")
+ py = ffi.new("int *") arr = ffi.new("int[2]")
+ lib.fetch_size(px, py) -OR- lib.fetch_size(arr, arr + 1)
+ x = px[0] x = arr[0]
+ y = py[0] y = arr[1]
+
+ p_handle = ffi.new("opaque_t **")
+ lib.init_stuff(p_handle) # pass the pointer to the 'handle' pointer
+ handle = p_handle[0] # now we can read 'handle' out of 'p_handle'
+ lib.more_stuff(handle)
.. __: ref.html#ffi-addressof
+
Any operation that would in C return a pointer or array or struct type
gives you a fresh cdata object. Unlike the "original" one, these fresh
cdata objects don't have ownership: they are merely references to
@@ -208,7 +235,7 @@
string stored in the source array (adding surrogates if necessary).
See the `Unicode character types`__ section for more details.
-__: ref.html#unichar
+.. __: ref.html#unichar
Note that unlike Python lists or tuples, but like C, you *cannot* index in
a C array from the end using negative numbers.
diff --git a/doc/source/whatsnew.rst b/doc/source/whatsnew.rst
--- a/doc/source/whatsnew.rst
+++ b/doc/source/whatsnew.rst
@@ -11,7 +11,7 @@
when used as ``charN_t *`` or ``charN_t[]`` they represent a unicode
string. The difference with ``wchar_t`` is that they have a known,
fixed size. They should work at all places that used to work with
- ``wchar_t`` (please report an issue if I missing something). Note
+ ``wchar_t`` (please report an issue if I missed something). Note
that with ``set_source()``, you need to make sure that these types are
actually defined by the C source you provide (if used in ``cdef()``).
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