This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-10-26

1219. Non-static data member initializers in constant expressions

[Voted into the WP at the March, 2011 meeting as part of paper N3262.]

The current treatment of constexpr constructors and constant expressions does not deal with the initializers for non-static data members, which should also be required to be constant expressions.

Proposed resolution (November, 2010) [SUPERSEDED]:

1. Change 6.9.3.2 [basic.start.static] paragraph 2 as follows:

• if an object with static or thread storage duration is initialized by a constructor call, if the constructor is a constexpr constructor, if all constructor arguments are constant expressions (including conversions), and if, after function invocation substitution (9.2.6 [dcl.constexpr]), every constructor call and full-expression in the mem-initializers and in the brace-or-equal-initializers for non-static data members is a constant expression

2. Change 6.8 [basic.types] paragraph 10 as follows (wording assumes the proposed resolution of issue 981)

A type is a literal type if it is:

• a scalar type; or

• a class type (Clause 11 [class]) that has all of the following properties:

• it has a trivial destructor,

• every constructor call and full-expression in the brace-or-equal-initializers for non-static data members (if any) is a constant expression (7.7 [expr.const]),

• it is an aggregate type (9.4.2 [dcl.init.aggr]) or has at least one constexpr constructor or constructor template that is not a copy or move constructor, and

• it has all non-static data members and base classes of literal types; or

• an array of literal type.