Re: [boost] [python] Tru64/CXX function template issues

From: David Abrahams (dave_at_[hidden])
Date: 2005-06-15 11:49:54

Markus Schöpflin <markus.schoepflin_at_[hidden]> writes:

> Hello,
>
> unfortunately boost.python is unusable on that platform because most of the 
> tests fail at runtime with a stack overflow. The reason is illustrated in 
> the following code sample:
>
> ---%<---
> void foo(int);
> template <class T> void foo(T) { foo(0); }
>
> int main()
> {
>    foo(0);
> }
> --->%---
>
> When compiling this with CXX 6.5, the code compiles and links cleanly, 
> despite the fact that the overload for foo() is not defined. Instead the 
> compiler instantiates foo<int>(int) and then uses the instantiation for the 
> call to foo() which of course leads to a stack overflow.

I'm confused.  I was pretty sure Ralf was running Boost.Python on that
compiler.  Ralf?

> I had a look at the standard what should happen in this case, but after 
> reading [temp.over] I'm not really sure if we don't indeed end up with two 
> candidate functions for the overload resolution of foo(), one being the 
> overload itself and the other the specialization of the function template 
> for int. Could anyone please clarify this?

The non-template function should be preferred.  The function template
should never even get instantiated.

> As for a possible workaround, replacing the overload with a specialization 
> of the function template would work, AFAICT. Would such a patch be accepted?

If it's a localized patch somewhere in Boost.Python, it might.  But
this sounds like the sort of problem that would require sweeping
fixes.  No?

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