Re: [PATCH] Define std::__invoke_r for INVOKE<R>

[Jonathan Wakely <jwakely at redhat dot com>]

On 17/05/19 10:15 +0100, Jonathan Wakely wrote:
> I'm testing the attached fix. Thanks for the report.

Tests passed, patch committed to trunk.


> commit 6ae6283255f58ad44a159970dce6f431cf46f293
> Author: Jonathan Wakely <jwakely@redhat.com>
> Date:   Fri May 17 10:10:10 2019 +0100
>
>    Fix __invoke_r<void> to be valid in C++11
>    
>            * include/bits/invoke.h [__cplusplus < 201703L] (__invoke_r<void>):
>            Use _GLIBCXX14_CONSTEXPR because void functions cannot be constexpr
>            in C++11.
>
> diff --git a/libstdc++-v3/include/bits/invoke.h b/libstdc++-v3/include/bits/invoke.h
> index 59e22da84d4..b2e9eee1a48 100644
> --- a/libstdc++-v3/include/bits/invoke.h
> +++ b/libstdc++-v3/include/bits/invoke.h
> @@ -144,7 +144,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
>   // INVOKE<R> when R is cv void
>   template<typename _Res, typename _Callable, typename... _Args>
> -    constexpr __can_invoke_as_void<_Res, _Callable, _Args...>
> +    _GLIBCXX14_CONSTEXPR __can_invoke_as_void<_Res, _Callable, _Args...>
>     __invoke_r(_Callable&& __fn, _Args&&... __args)
>     {
>       using __result = __invoke_result<_Callable, _Args...>;