[c++-concepts]: constraint association

[Gabriel Dos Reis]

On Sat, Jun 22, 2013 at 12:11 PM, Gabriel Dos Reis <gdr@axiomatics.org> wrote:
> Andrew Sutton <andrew.n.sutton@gmail.com> writes:
>
> | I the long term, I think we'll end up having constraints attached to
> | declarations wherever we constrain auto (PARM_DECL, VAR_DECL, etc).
> | Although now that I'm looking, it seems that lang_decl_parm does not
> | inherit lang_min. Hmm...
> |
> | Mostly, though, I'm not sure where I could put it where both
> | TEMPLATE_DECL and FUNCTION_DECL would have constraints.
>
> I think we want constraints for:
>
>   * FUNCTION_DECL
>   * TEMPLATE_DECL
>   * TYPE_DECL
>   * TEMPLATE_PARM_DECL

Well, thinking more about it, I believe we want it only for
   * TEMPLATE_DECL
   * TEMPLATE_PARM_DECL.

The FUNCTION_DECL and the TYPE_DECL gets their constraints
from the abstract instantiation of the associated TEMPLATE_DECL.

The comment for PARM_DECL extends to VAR_DECL -- only temploids
get constraints and non-temploid vars declared 'auto' at the source
level have types
that are TEMPLATE_TYPE_PARM, hence should get their constraints properly set.

-- Gaby