libstdc++: Fix exposure of TU-local lambda in __detail::__func_handle_t.

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.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 7c5ac931e313ba7158456f6ab61c96fa0df0c094..b3105c55383965e3ecd8007eedf70ca758d56239 100644 (file)
--- 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.