Re: [PATCH] c++: CTAD and deduction guide selection [PR86439]

2021-06-22 Thread Jonathan Wakely via Gcc-patches
On Wed, 23 Jun 2021, 05:20 Patrick Palka via Libstdc++, < libstd...@gcc.gnu.org> wrote: > On Tue, 22 Jun 2021, Jonathan Wakely wrote: > > > On Tue, 22 Jun 2021 at 19:45, Patrick Palka wrote: > > > This change causes us to reject some container CTAD examples in the > > > libstdc++ testsuite due to

Re: [PATCH] c++: CTAD and deduction guide selection [PR86439]

2021-06-22 Thread Patrick Palka via Gcc-patches
On Tue, 22 Jun 2021, Jonathan Wakely wrote: > On Tue, 22 Jun 2021 at 19:45, Patrick Palka wrote: > > This change causes us to reject some container CTAD examples in the > > libstdc++ testsuite due to deduction failure for {}, which AFAICT is the > > correct behavior. Previously, in the case of e.

Re: [PATCH] c++: CTAD and deduction guide selection [PR86439]

2021-06-22 Thread Jonathan Wakely via Gcc-patches
On Tue, 22 Jun 2021 at 19:45, Patrick Palka wrote: > This change causes us to reject some container CTAD examples in the > libstdc++ testsuite due to deduction failure for {}, which AFAICT is the > correct behavior. Previously, in the case of e.g. the first removed > example for std::map, the type

Re: [PATCH] c++: CTAD and deduction guide selection [PR86439]

2021-06-22 Thread Jason Merrill via Gcc-patches
On 6/22/21 2:45 PM, Patrick Palka wrote: During CTAD, we select the best viable deduction guide via build_new_function_call, which performs overload resolution on the set of candidate guides and then forms a call to the guide. As the PR points out, this latter step is unnecessary and occasionall

[PATCH] c++: CTAD and deduction guide selection [PR86439]

2021-06-22 Thread Patrick Palka via Gcc-patches
During CTAD, we select the best viable deduction guide via build_new_function_call, which performs overload resolution on the set of candidate guides and then forms a call to the guide. As the PR points out, this latter step is unnecessary and occasionally gives us the wrong answer since a call to