On Thu, 27 Nov 2025 at 13:57, Tomasz Kamiński <[email protected]> wrote:
>
> The lambda is considered to be TU-local entity, use a named function
> instead.
>
> As drive-by, a functor stored inside __func_handle::_Inplace is renamed
> to _M_fn, as we no longer limit the functor type to function pointers.
>
> libstdc++-v3/ChangeLog:
>
> * include/std/ranges (__func_handle::__select): Named function
> extracted from local lambda.
> (__detail::__func_handle_t): Define using __func_handle::__select.
> (__func_handle::_Inplace): Raname _M_ptr to _M_fn.
"Rename"
> ---
> v2 makes __func_handle::__select conteval and do rename as drive-by.
> OK for trunk?
OK
>
> libstdc++-v3/include/std/ranges | 45 ++++++++++++++++++---------------
> 1 file changed, 25 insertions(+), 20 deletions(-)
>
> diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
> index 7c5ac931e31..b3105c55383 100644
> --- a/libstdc++-v3/include/std/ranges
> +++ b/libstdc++-v3/include/std/ranges
> @@ -346,23 +346,23 @@ namespace ranges
>
> constexpr explicit
> _Inplace(_Fn __func) noexcept
> - : _M_ptr(__func)
> + : _M_fn(__func)
> { }
>
> template<typename... _Iters>
> constexpr decltype(auto)
> _M_call_deref(const _Iters&... __iters) const
> - noexcept(noexcept(_M_ptr(*__iters...)))
> - { return _M_ptr(*__iters...); }
> + noexcept(noexcept(_M_fn(*__iters...)))
> + { return _M_fn(*__iters...); }
>
> template<typename _DistType, typename... _Iters>
> constexpr decltype(auto)
> _M_call_subscript(const _DistType __n, const _Iters&...
> __iters) const
> -
> noexcept(noexcept(_M_ptr(__iters[iter_difference_t<_Iters>(__n)]...)))
> - { return _M_ptr(__iters[iter_difference_t<_Iters>(__n)]...); }
> +
> noexcept(noexcept(_M_fn(__iters[iter_difference_t<_Iters>(__n)]...)))
> + { return _M_fn(__iters[iter_difference_t<_Iters>(__n)]...); }
>
> private:
> - [[no_unique_address]] _Fn _M_ptr = _Fn();
> + [[no_unique_address]] _Fn _M_fn = _Fn();
> };
>
> template<typename _Fn>
> @@ -448,23 +448,28 @@ namespace ranges
>
> noexcept(noexcept(_Fn::operator()(__iters[iter_difference_t<_Iters>(__n)]...)))
> { return
> _Fn::operator()(__iters[iter_difference_t<_Iters>(__n)]...); }
> };
> +
> + template<typename _Fn, typename... _Iters>
> + consteval auto
> + __select()
> + {
> + using _Fd = remove_cv_t<_Fn>;
> + if constexpr (is_member_pointer_v<_Fd>)
> + return __func_handle::_InplaceMemPtr<_Fd>();
> + else if constexpr (is_function_v<remove_pointer_t<_Fd>>)
> + return __func_handle::_Inplace<_Fd>();
> + else if constexpr (__is_std_op_wrapper<_Fd>)
> + return __func_handle::_Inplace<_Fd>();
> + else if constexpr (requires (const _Iters&... __iters)
> + { _Fd::operator()(*__iters...); })
> + return __func_handle::_StaticCall<_Fd>();
> + else
> + return __func_handle::_ViaPointer<_Fn>();
> + };
> } // __func_handle
>
> template<typename _Fn, typename... _Iters>
> - using __func_handle_t = decltype([] {
> - using _Fd = remove_cv_t<_Fn>;
> - if constexpr (is_member_pointer_v<_Fd>)
> - return __func_handle::_InplaceMemPtr<_Fd>();
> - else if constexpr (is_function_v<remove_pointer_t<_Fd>>)
> - return __func_handle::_Inplace<_Fd>();
> - else if constexpr (__is_std_op_wrapper<_Fd>)
> - return __func_handle::_Inplace<_Fd>();
> - else if constexpr (requires (const _Iters&... __iters)
> - { _Fd::operator()(*__iters...); })
> - return __func_handle::_StaticCall<_Fd>();
> - else
> - return __func_handle::_ViaPointer<_Fn>();
> - }());
> + using __func_handle_t = decltype(__func_handle::__select<_Fn,
> _Iters...>());
> } // namespace __detail
>
> /// A view that contains exactly one element.
> --
> 2.51.1
>
