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Add note about specifying custom base class for Exceptions. #2465

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Sep 6, 2020
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Add note about specifying custom base class for Exceptions. #2465

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Add note about specifying custom base.
michalsustr Sep 5, 2020
68f9eba
Update exception docs based on PR feedback.
michalsustr Sep 5, 2020
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Fix trailing whitespace.
michalsustr Sep 5, 2020
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13 changes: 13 additions & 0 deletions docs/advanced/exceptions.rst
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Expand Up @@ -79,6 +79,19 @@ This call creates a Python exception class with the name ``PyExp`` in the given
module and automatically converts any encountered exceptions of type ``CppExp``
into Python exceptions of type ``PyExp``.

It is possible to specify base class for the exception using the third
parameter, a pointer to `PyObject`:
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I know this is currently correct, but do we have any idea why this isn't a handle?

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No idea, first time contributing to pybind.

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No problem. Let's see if @bstaletic or anyone else knows! :-)

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Nope, no clue other than "the source says so".

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OK, let's maybe change this in a different PR, then? (Actually, we might even change this to py::type, @henryiii?)


.. code-block:: cpp

py::register_exception<CppExp>(module, "PyExp", PyExc_RuntimeError);

Then `PyExp` can be caught both as `PyExp` and `RuntimeError`.

The class objects of the built-in Python exceptions are listed in the Python
documentation on `Standard Exceptions <https://docs.python.org/3/c-api/exceptions.html#standard-exceptions>`_.
The default base class is `PyExc_Exception`.

When more advanced exception translation is needed, the function
``py::register_exception_translator(translator)`` can be used to register
functions that can translate arbitrary exception types (and which may include
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