Proposed resolution (approved by CWG 2025-10-10):

1. Change in 7.6.2.8 [expr.new] bullet 8.4 as follows:

   If the expression in a noptr-new-declarator is present, it is implicitly converted to std::size_t. The value of the expression is invalid if

   • ...
   • the new-initializer is a braced-init-list or a parenthesized expression-list and the number of array elements for which initializers are provided (including the terminating '\0' in a string-literal (5.13.5 [lex.string])) exceeds the number of elements to initialize.

2. Change in 7.6.2.8 [expr.new] paragraph 9 as follows:

   If the allocated type is an array, the new-initializer is a braced-init-list or a parenthesized expression-list, and the expression is potentially-evaluated and not a core constant expression, the semantic constraints of copy-initializing a hypothetical element of the array from an empty initializer list are checked as follows:

   • If the new-initializer is a braced-init-list, the hypothetical element is copy-initialized from an empty initializer list (9.5.5 [dcl.init.list]).
   • Otherwise, the hypothetical element is value-initialized (9.5.1 [dcl.init.general]).

   [Note 5: The array can contain more elements than there are elements in the braced-init-list new-initializer, requiring initialization of the remainder of the array elements from an empty initializer list as appropriate. —end note]

(From submission #685.)

Subclause 7.6.2.8 [expr.new] paragraph 8 and paragraph 9 contain special cases involving aggregate initialization using braced-init-lists, which need to be amended for parenthesized aggregate initialization. The corresponding rules for the initialization of variables are in 9.5.1 [dcl.init.general] bullet 16.5 for arrays and in 9.5.1 [dcl.init.general] bullet 16.6.2.2 for aggregate classes.

Possible resolution (March, 2025) [SUPERSEDED]:

1. Change in 7.6.2.8 [expr.new] bullet 8.4 as follows:

   If the expression in a noptr-new-declarator is present, it is implicitly converted to std::size_t. The value of the expression is invalid if

   • ...
   • the new-initializer is a braced-init-list present and the number of array elements for which initializers are provided (including the terminating '\0' in a string-literal (5.13.5 [lex.string])) in a braced-init-list or parenthesized expression-list exceeds the number of elements to initialize.

2. Change in 7.6.2.8 [expr.new] paragraph 9 as follows:

   If the allocated type is an array, the new-initializer is a braced-init-list present and is not (), and the expression is potentially-evaluated and not a core constant expression, the semantic constraints of copy-initializing a hypothetical element of the array from an empty initializer list are checked as follows:

   • If the new-initializer is a braced-init-list, the hypothetical element is copy-initialized from an empty initializer list (9.5.5 [dcl.init.list]).
   • If the new-initializer is a parenthesized expression-list, the hypothetical element is value-initialized (9.5.1 [dcl.init.general]).

   [Note 5: The array can contain more elements than there are elements in the braced-init-list new-initializer, requiring initialization of the remainder of the array elements from an empty initializer list as appropriate. —end note]

Possible resolution (per CWG reflector review starting 2025-05-07) [SUPERSEDED]:

1. Change in 7.6.2.8 [expr.new] bullet 8.4 as follows:

   If the expression in a noptr-new-declarator is present, it is implicitly converted to std::size_t. The value of the expression is invalid if

   • ...
   • the new-initializer is a braced-init-list present and the number of array elements for which initializers are provided (including the terminating '\0' in a string-literal (5.13.5 [lex.string])) in a braced-init-list or parenthesized expression-list exceeds the number of elements to initialize.

2. Change in 7.6.2.8 [expr.new] paragraph 9 as follows:

   If the allocated type is an array, the new-initializer is a braced-init-list present, and the expression is potentially-evaluated and not a core constant expression, the semantic constraints of copy-initializing a hypothetical element of the array from an empty initializer list are checked as follows:

   • If the new-initializer is a braced-init-list, the hypothetical element is copy-initialized from an empty initializer list (9.5.5 [dcl.init.list]).
   • If the new-initializer is a parenthesized expression-list, the hypothetical element is value-initialized (9.5.1 [dcl.init.general]).

   [Note 5: The array can contain more elements than there are elements in the braced-init-list new-initializer, requiring initialization of the remainder of the array elements from an empty initializer list as appropriate. —end note]