This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 114a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-04-18
[Accepted as a DR at the June, 2023 meeting.]
Consider:
template <auto V>
void foo() {}
void bar() {
foo<[i = 3] { return i; }>();
}
It is unclear whether the data members of a closure type are public or private. This makes a difference, since it affects whether a closure type is a structural type or not (13.2 [temp.param] paragraph 7:
A structural type is one of the following:
- a scalar type, or
- an lvalue reference type, or
- a literal class type with the following properties:
- all base classes and non-static data members are public and non-mutable and
- the types of all bases classes and non-static data members are structural types or (possibly multi-dimensional) array thereof.
Proposed resolution (approved by CWG 2023-03-30):
Change in 7.5.5.2 [expr.prim.lambda.closure] paragraph 2 as follows:
... The closure type is not an aggregate type (9.4.2 [dcl.init.aggr]) and not a structural type (13.2 [temp.param]). ...