This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112c. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2023-11-10
Consider an example like:
struct A { struct B { auto foo() { return 0; } }; decltype(B().foo()) x; };
There does not appear to be a prohibition of cases like this, where the type of a member depends on the definition of a member function.
(See also issues 1360, 1397, and 2335.)
Additional notes (January, 2023):
The following example might be related:
#include <type_traits> struct Bar { struct Baz { int a = 0; }; static_assert(std::is_default_constructible_v<Baz>); };