Re: [boost] BPL: How do you get python to use C++ function arg defaults?

From: David Abrahams (abrahams_at_[hidden])
Date: 2001-03-08 23:44:26

----- Original Message ----- 
From: <rcspython_at_[hidden]>

> I wrapped a class with some methods of the type...
> 
> char * myclass::myfunc(int mynum, const char * mystring = NULL)
> 
> Now, the wrapped class method does work.. however, when I was testing 
> it under the interactive python session, it complained that function 
> requires 3 parameters, and I had only provided 2 as in:
> 
> import mywrap
> 
> mw = mywrap(1)
> mw.myfunc(1) // it didn't like this...
> 
> Shouldn't the NULL default be used by the python call?
> 
> It didn't complain when I did
> 
> mw.myfunc(1,"") // This worked but defeats the purpose of using 
> defaults

There isn't yet any support for using default parameters in Boost.Python
You can emulate it by creating a forwarding function in C++:

char* myclass_myfunc1(myclass& self, int x) { self.myfunc(x); }

and exposing that function as "myfunc" using the overloading feature.

Sorry, it's the best I can do for now!

-Dave