From 3a679eaf00b909980ad38344ec0c7395adcd0564 Mon Sep 17 00:00:00 2001 From: Peter Hinch <peter@hinch.me.uk> Date: Sat, 17 Aug 2019 13:50:21 +0100 Subject: [PATCH] docs/reference/speed_python: Update that read-only buffers are accepted. As allowed by recent cd35dd9d9a29836906acdce60c931f6352b536d0 --- docs/reference/speed_python.rst | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/docs/reference/speed_python.rst b/docs/reference/speed_python.rst index c5aa80c6e..f2d7739fb 100644 --- a/docs/reference/speed_python.rst +++ b/docs/reference/speed_python.rst @@ -293,10 +293,12 @@ microseconds. The rules for casting are as follows: * The argument to a bool cast must be integral type (boolean or integer); when used as a return type the viper function will return True or False objects. * If the argument is a Python object and the cast is ``ptr``, ``ptr``, ``ptr16`` or ``ptr32``, - then the Python object must either have the buffer protocol with read-write capabilities - (in which case a pointer to the start of the buffer is returned) or it must be of integral - type (in which case the value of that integral object is returned). - + then the Python object must either have the buffer protocol (in which case a pointer to the + start of the buffer is returned) or it must be of integral type (in which case the value of + that integral object is returned). + +Writing to a pointer which points to a read-only object will lead to undefined behaviour. + The following example illustrates the use of a ``ptr16`` cast to toggle pin X1 ``n`` times: .. code:: python -- GitLab