Re: [PATCH,c++] describe reasons for function template overload resolution failure

[Mark Mitchell <mark@codesourcery.com>]

On 2/2/2011 1:05 PM, Nathan Froyd wrote:

> In my patch for PR 45329, diagnostics for overload resolution failure, I
> overlooked one very important class of failures: failures when dealing
> with overload candidates that are function templates.  Specifically, we
> ought to diagnose any reasons why template argument deduction failed.
> The patch below attempts to rectify that situation.  It's a bit big for
> stage 4; it'd be great if it went in to 4.6, but I expect this to go in
> for the 4.7 timeframe.  It's also not quite done, so I'd appreciate
> feedback on whether the idea and implementation are sound.

I think the idea is sound and the improved diagnostics valuable.

I do think that, though, this is 4.7 material -- it just doesn't seem
bug-fixy enough for 4.6.

> I chose to permit NULL unification_infos to be passed around; I think
> it'd be just as valid to require the unification_info to be non-NULL,
> though.

I don't have an opinion on this -- I think either way is perfectly
reasonable.  I guess, in general, requiring a non-NULL input is a bit
less error-prone, though, so I might tend that way.  A caller that
doesn't want the info can always just ignore the result...

Thank you,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713