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### 154. Missing `double` specifier for `do_get()`

Section: 30.4.3.2.3 [facet.num.get.virtuals] Status: TC1 Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

The table in paragraph 7 for the length modifier does not list the length modifier `l` to be applied if the type is `double`. Thus, the standard asks the implementation to do undefined things when using `scanf()` (the missing length modifier for `scanf()` when scanning `double`s is actually a problem I found quite often in production code, too).

Proposed resolution:

In 30.4.3.2.3 [facet.num.get.virtuals], paragraph 7, add a row in the Length Modifier table to say that for `double` a length modifier `l` is to be used.

Rationale:

The standard makes an embarrassing beginner's mistake.