[C++-sig] working around the non-const Python C API

[David Abrahams]

Jeremy Hylton <jeremy at alum.mit.edu> writes:

> I was curious if anyone had advice on how to work around the fact that
> much of the Python C API asks for char* when it really intends to
> treat it as a const char*.  An example of this behavior is the
> PyMethodDef struct, which has char* ml_name and char* ml_doc
> parameters.  If you use a string literal, you get a warning about
> casting a const char* to a char*.  

In C++, anyway, these are really supposed to be hard errors.  The type
of a string literal is char const(&)[N].  

> I can add a cast around each literal, but that's really ugly.
>
> Is there a good way to avoid the warnings?

Fix Python :)

> Secondarily, I know that python-dev is a bit hesitant about const
> correctness, but we did get some const char* types added with the new
> bytecode compiler.  Perhaps it's worthwhile to try changing a few of
> the most egregious cases to use const char*.

If you can't do that, the next most good approach is to use const_cast
instead of a C-style cast.  Just to drive the point home :)

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com