Re: [boost] [regex] Clearing failures in regex_regress on Tru64/CXX

From: Markus Schöpflin (markus.schoepflin_at_[hidden])
Date: 2005-06-29 09:12:17

Christoph Ludwig wrote:

> On Wed, Jun 29, 2005 at 02:52:12PM +0200, Markus Schöpflin wrote:

>>Christoph Ludwig wrote:

>>>Section 10.5:
>>>  The standard also specifies that there can be at most one explicit
>>>  instantiation of a certain template specialization in a
>>>  program. Furthermore, if a template specialization is explicitly
>>>  instantiated, it should not be explicitly specialized, and vice versa.
>>
>>I can't find anything in the standard (14.7) indicating this.

> OK, I overcame my laziness :-) It is 14.7p5:
> 
>   No program shall explicitly instantiate any template more than once, both
>   explicitly instantiate and explicitly specialize a template, or specialize a
>   template more than once for a given set of template arguments. 
>   An implementation is not required to diagnose a violation of this rule.
> 
> I admit I find Vandvoorde's and Josuttis' phrasing much easier to grok.

Duh, I read 14.7.2 and 14.7.3 over and over and I completely missed that 
one. :-(

Hmm, now I'm left wondering how in general to deal with this issue. Would 
this be legal?

---%<---
template <class T>
struct foo {
   static T bar() { static T t; return t; }
};

template<> foo<int>;
template int foo<int>::bar();
--->%--

Time to ask the compiler vendor on how to avoid multiple copies of t here, 
I think.

Thanks, Markus