Re: [boost] C++11 Metaprogramming

Subject: Re: [boost] C++11 Metaprogramming
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2012-04-01 17:39:54

> >  From a pure meta-programming perspective, I guess the only real 
> > addition is variadic templates.
> > However, there is the problem that they're fairly limited and that one 
> > may not expand them as the arguments of a non-variadic template.
> 
> I thought that was allowed. At least, GCC supports it since 4.7, and its
> error message for it in 4.6 was 
> 
> "sorry, unimplemented: cannot expand 'Args ...' into a fixed-length argument list"
> 
> which suggests the feature is not an extension.

The relevant GCC bug report is PR 35722 [1].

It is mentioned there that the change that made this valid was the incorporation

of N2555 [2]. Note in particular the sentence in section 14.3 paragraph 8 that

was struck.

Regards,

Nate

[1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35722

[2] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2555.pdf