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### 566. array forms of unformatted input function undefined for zero-element arrays

Section: 29.7.4.4 [istream.unformatted] Status: CD1 Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

The array forms of unformatted input functions don't have well-defined semantics for zero-element arrays in a couple of cases. The affected ones (`istream::get()` and `getline()`) are supposed to terminate when `(n - 1)` characters are stored, which obviously can never be true when `(n == 0)` to start with.

Proposed resolution:

I propose the following changes (references are relative to the Working Draft (document N1804).

Change 27.6.1.3, p8 (`istream::get()`), bullet 1 as follows:

> if `(n < 1)` is true or `(n - 1)` characters are stored;

Similarly, change 27.6.1.3, p18 (`istream::getline()`), bullet 3 as follows:

> `(n < 1)` is true or `(n - 1)` characters are stored (in which case the function calls `setstate(failbit)`).

Finally, change p21 as follows:

> In any case, provided `(n > 0)` is true, it then stores a null character (using charT()) into the next successive location of the array.