more .pxd signature fixing

Cython/Includes/python_buffer.pxd

@@ -25,23 +25,85 @@ cdef extern from "Python.h":
         PyBUF_WRITE,
         PyBUF_SHADOW
 
-    int PyObject_CheckBuffer(object obj)
-    int PyObject_GetBuffer(object obj, Py_buffer *view, int flags)
-    void PyObject_ReleaseBuffer(object obj, Py_buffer *view)
+    bint PyObject_CheckBuffer(object obj)
+    # Return 1 if obj supports the buffer interface otherwise 0.
+
+    int PyObject_GetBuffer(object obj, Py_buffer *view, int flags) except -1
+    # Export obj into a Py_buffer, view. These arguments must never be
+    # NULL. The flags argument is a bit field indicating what kind of
+    # buffer the caller is prepared to deal with and therefore what
+    # kind of buffer the exporter is allowed to return. The buffer
+    # interface allows for complicated memory sharing possibilities,
+    # but some caller may not be able to handle all the complexity but
+    # may want to see if the exporter will let them take a simpler
+    # view to its memory.
+
+    # Some exporters may not be able to share memory in every possible
+    # way and may need to raise errors to signal to some consumers
+    # that something is just not possible. These errors should be a
+    # BufferError unless there is another error that is actually
+    # causing the problem. The exporter can use flags information to
+    # simplify how much of the Py_buffer structure is filled in with
+    # non-default values and/or raise an error if the object can’t
+    # support a simpler view of its memory.
+
+    # 0 is returned on success and -1 on error.
+
+    void PyBuffer_Release(object obj, object view)
+    # Release the buffer view over obj. This should be called when the
+    # buffer is no longer being used as it may free memory from it.
+
     void* PyBuffer_GetPointer(Py_buffer *view, Py_ssize_t *indices)
+    # ??
+
     int PyBuffer_SizeFromFormat(char *) # actually const char
+    # Return the implied ~Py_buffer.itemsize from the struct-stype
+    # ~Py_buffer.format
+
     int PyBuffer_ToContiguous(void *buf, Py_buffer *view, Py_ssize_t len, char fort)
+    # ??
+
     int PyBuffer_FromContiguous(Py_buffer *view, void *buf, Py_ssize_t len, char fort)
+    # ??
+
+    int PyObject_CopyToObject(object obj, void *buf, Py_ssize_t len, char fortran) except -1
+    # Copy len bytes of data pointed to by the contiguous chunk of
+    # memory pointed to by buf into the buffer exported by obj. The
+    # buffer must of course be writable. Return 0 on success and
+    # return -1 and raise an error on failure. If the object does not
+    # have a writable buffer, then an error is raised. If fortran is
+    # 'F', then if the object is multi-dimensional, then the data will
+    # be copied into the array in Fortran-style (first dimension
+    # varies the fastest). If fortran is 'C', then the data will be
+    # copied into the array in C-style (last dimension varies the
+    # fastest). If fortran is 'A', then it does not matter and the
+    # copy will be made in whatever way is more efficient.
+
     int PyObject_CopyData(object dest, object src)
-    int PyBuffer_IsContiguous(Py_buffer *view, char fort)
+    # Copy the data from the src buffer to the buffer of destination
+
+    bint PyBuffer_IsContiguous(Py_buffer *view, char fort)
+    # Return 1 if the memory defined by the view is C-style (fortran
+    # is 'C') or Fortran-style (fortran is 'F') contiguous or either
+    # one (fortran is 'A'). Return 0 otherwise.
+
     void PyBuffer_FillContiguousStrides(int ndims, 
                                         Py_ssize_t *shape, 
                                         Py_ssize_t *strides,
                                         int itemsize,
                                         char fort)
+    # Fill the strides array with byte-strides of a contiguous
+    # (Fortran-style if fort is 'F' or C-style otherwise) array of the
+    # given shape with the given number of bytes per element.
+
     int PyBuffer_FillInfo(Py_buffer *view, void *buf,
                           Py_ssize_t len, int readonly,
-                          int flags)
+                          int flags) except -1
+    # Fill in a buffer-info structure, view, correctly for an exporter
+    # that can only share a contiguous chunk of memory of “unsigned
+    # bytes” of the given length. Return 0 on success and -1 (with
+    # raising an error) on error.
 
-    object PyObject_Format(object obj,
-                           object format_spec)
+    object PyObject_Format(object obj, object format_spec)
+    # Takes an arbitrary object and returns the result of calling
+    # obj.__format__(format_spec).