Fix for template method pointer parameter issue

[darryllawson]

I have found that Breathe does not cope with a template method pointer parameter.

The method signature of bad() below causes the issue.

/**
 * A class.
 */
class C {
public:
    /**
     * Set a callback. This causes a breathe error.
     *
     * \tparam OWNER Class the declares \p callback.
     * \param owner Reference to the object to call \p callback on.
     * \param callback Pointer to callback method.
     */
    template <typename OWNER>
    void bad(OWNER& owner, void (OWNER::*callback)(void));


    /**
     * No error from this because does not have method pointer param.
     *
     * \tparam OWNER Class the declares \p callback.
     * \param owner Reference to the object to call \p callback on.
     * \param v Some parameter.
     */
    template <typename OWNER>
    void fine(OWNER& owner, int v);
};

This is the Sphinx source to reproduce the error:

Welcome to breathe-issue's documentation!
=========================================

Doco for C:

.. doxygenclass:: C
    :members:

And this is the warning reported by Sphinx:

index.rst:6: WARNING: Error when parsing function declaration.
If the function has no return type:
  Error in declarator or parameters and qualifiers
  Invalid definition: Expected identifier in nested name, got keyword: void [error at 28]
    template<typename OWNER>void C::bad(OWNER & owner, void(OWNER::*)(void) callback)
    ----------------------------^
If the function has a return type:
  Error in declarator or parameters and qualifiers
  If pointer to member declarator:
    Invalid definition: Expected '::' in pointer to member (function). [error at 35]
      template<typename OWNER>void C::bad(OWNER & owner, void(OWNER::*)(void) callback)
      -----------------------------------^
  If declarator-id:
    Invalid definition: Expecting "," or ")" in parameters_and_qualifiers, got "c". [error at 72]
      template<typename OWNER>void C::bad(OWNER & owner, void(OWNER::*)(void) callback)
      ------------------------------------------------------------------------^
looking for now-outdated files... none found

The proposed fix is just a tweak to the regex that is trying to match a function pointer parameter type.

Please let me know if there is anything else I can do to help on this.

Thanks for providing Breathe too!

[vermeeren]

Hi, thanks for the patch, the modified regex seems fine.

Merged manually to cleanup the commits, will bump version and release breathe v4.13.1 in a bit.

[darryllawson]

Thank you so much for the lightning fast turn around! And for your broader efforts on Breathe.