prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  [BUG] Annotated attributes of cclass are not supporting pointers
  <!--
  **PLEASE READ THIS FIRST:**
  - Do not use the bug and feature tracker for support requests. Use the `cython-users` mailing list instead.
  - Did you search for similar issues already? Please do, it helps to save us precious time that we otherwise could not invest into development.
  - Did you try the latest master branch or pre-release? It might already have what you want to report. Also see the [Changelog](https://github.com/cython/cython/blob/master/CHANGES.rst) regarding recent changes.
  -->
  
  **Describe the bug**
  The compilation is failing, when attribute of cclass is declared using annotated type containing pointer.
  
  **To Reproduce**
  Following code:
  ```python
  import cython
  
  @cython.cclass
  class Foo:
      a: cython.pointer(cython.int)
  
      def bar(self):
          self.a = cython.NULL
  ```
  fails during compilation with error:
  ```
  $ cython -3 test.py
  
  Error compiling Cython file:
  ------------------------------------------------------------
  ...
  @cython.cclass
  class Foo:
      a: cython.pointer(cython.int)
  
      def bar(self):
          self.a = cython.NULL
                        ^
  ------------------------------------------------------------
  
  test.py:8:23: Cannot convert 'void *' to Python object
  ```
  
  **Expected behavior**
  Compilation should be successfull.
  
  **Environment (please complete the following information):**
   - OS: Linux
   - Python version: Python 3.9.2
   - Cython version: master
  
  **Additional context**
  When `declare()` statement or `cython.p_int` type is used, compilation is successful:
  
  ```python
  import cython
  
  @cython.cclass
  class Foo:
      a = cython.declare(cython.pointer(cython.int))
  
      def bar(self):
          self.a = cython.NULL
  ```
  
  ```python
  import cython
  
  @cython.cclass
  class Foo:
      a: cython.p_int
  
      def bar(self):
          self.a = cython.NULL
  ```
  
  
  </issue>
  <code>
  [start of docs/examples/tutorial/clibraries/queue.py]
  1 from cython.cimports import cqueue
  2 
  3 @cython.cclass
  4 class Queue:
  5     _c_queue = cython.declare(cython.pointer(cqueue.Queue))
  6 
  7     def __cinit__(self):
  8         self._c_queue = cqueue.queue_new()
  9
  [end of docs/examples/tutorial/clibraries/queue.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/docs/examples/tutorial/clibraries/queue.py b/docs/examples/tutorial/clibraries/queue.py
  --- a/docs/examples/tutorial/clibraries/queue.py
  +++ b/docs/examples/tutorial/clibraries/queue.py
  @@ -2,7 +2,7 @@
   
   @cython.cclass
   class Queue:
  -    _c_queue = cython.declare(cython.pointer(cqueue.Queue))
  +    _c_queue: cython.pointer(cqueue.Queue)
   
       def __cinit__(self):
           self._c_queue = cqueue.queue_new()
  
verification_info: {"golden_diff": "diff --git a/docs/examples/tutorial/clibraries/queue.py b/docs/examples/tutorial/clibraries/queue.py\n--- a/docs/examples/tutorial/clibraries/queue.py\n+++ b/docs/examples/tutorial/clibraries/queue.py\n@@ -2,7 +2,7 @@\n \n @cython.cclass\n class Queue:\n-    _c_queue = cython.declare(cython.pointer(cqueue.Queue))\n+    _c_queue: cython.pointer(cqueue.Queue)\n \n     def __cinit__(self):\n         self._c_queue = cqueue.queue_new()\n", "issue": "[BUG] Annotated attributes of cclass are not supporting pointers\n<!--\r\n**PLEASE READ THIS FIRST:**\r\n- Do not use the bug and feature tracker for support requests. Use the `cython-users` mailing list instead.\r\n- Did you search for similar issues already? Please do, it helps to save us precious time that we otherwise could not invest into development.\r\n- Did you try the latest master branch or pre-release? It might already have what you want to report. Also see the [Changelog](https://github.com/cython/cython/blob/master/CHANGES.rst) regarding recent changes.\r\n-->\r\n\r\n**Describe the bug**\r\nThe compilation is failing, when attribute of cclass is declared using annotated type containing pointer.\r\n\r\n**To Reproduce**\r\nFollowing code:\r\n```python\r\nimport cython\r\n\r\n@cython.cclass\r\nclass Foo:\r\n    a: cython.pointer(cython.int)\r\n\r\n    def bar(self):\r\n        self.a = cython.NULL\r\n```\r\nfails during compilation with error:\r\n```\r\n$ cython -3 test.py\r\n\r\nError compiling Cython file:\r\n------------------------------------------------------------\r\n...\r\n@cython.cclass\r\nclass Foo:\r\n    a: cython.pointer(cython.int)\r\n\r\n    def bar(self):\r\n        self.a = cython.NULL\r\n                      ^\r\n------------------------------------------------------------\r\n\r\ntest.py:8:23: Cannot convert 'void *' to Python object\r\n```\r\n\r\n**Expected behavior**\r\nCompilation should be successfull.\r\n\r\n**Environment (please complete the following information):**\r\n - OS: Linux\r\n - Python version: Python 3.9.2\r\n - Cython version: master\r\n\r\n**Additional context**\r\nWhen `declare()` statement or `cython.p_int` type is used, compilation is successful:\r\n\r\n```python\r\nimport cython\r\n\r\n@cython.cclass\r\nclass Foo:\r\n    a = cython.declare(cython.pointer(cython.int))\r\n\r\n    def bar(self):\r\n        self.a = cython.NULL\r\n```\r\n\r\n```python\r\nimport cython\r\n\r\n@cython.cclass\r\nclass Foo:\r\n    a: cython.p_int\r\n\r\n    def bar(self):\r\n        self.a = cython.NULL\r\n```\r\n\n", "before_files": [{"content": "from cython.cimports import cqueue\n\n@cython.cclass\nclass Queue:\n    _c_queue = cython.declare(cython.pointer(cqueue.Queue))\n\n    def __cinit__(self):\n        self._c_queue = cqueue.queue_new()\n", "path": "docs/examples/tutorial/clibraries/queue.py"}]}