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### 867. Valarray and value-initialization

Section: 26.7.2.2 [valarray.cons] Status: NAD Editorial Submitter: Alberto Ganesh Barbati Opened: 2008-07-20 Last modified: 2016-01-28

Priority: Not Prioritized

View all other issues in [valarray.cons].

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Discussion:

From 26.7.2.2 [valarray.cons], paragraph 2:

>     explicit  valarray(size_t);

> > The array created by this constructor has a length equal to the value of the argument. The elements of the array are constructed using the default constructor for the instantiating type `T`.

The problem is that the most obvious `T`s for `valarray` are `float` and `double`, they don't have a default constructor. I guess the intent is to value-initialize the elements, so I suggest replacing:

> The elements of the array are constructed using the default constructor for the instantiating type `T`.

with

> The elements of the array are value-initialized.

There is another reference to the default constructor of `T` in the non-normative note in paragraph 9. That reference should also be replaced. (The normative wording in paragraph 8 refers to `T()` and so it doesn't need changes).

[ Batavia (2009-05): ]

> We agree with the proposed resolution. Move to NAD Editorial.

Proposed resolution:

Change 26.7.2.2 [valarray.cons], paragraph 2:

>     explicit  valarray(size_t);

> > The array created by this constructor has a length equal to the value of the argument. The elements of the array are constructed using the default constructor for the instantiating type `T` value-initialized (9.4 [dcl.init]).

Change 26.7.2.8 [valarray.members], paragraph 9:

> [Example: If the argument has the value -2, the first two elements of the result will be constructed using the default constructor value-initialized (9.4 [dcl.init]); the third element of the result will be assigned the value of the first element of the argument; etc. -- end example]