cpp/locale/numpunct/grouping

@1@ Public member function, calls the member function of the most derived class.

@2@ Returns an std holding, in each element, the number of digits in each group of the numeric output formatted by  (and, therefore, )

The groups are stored as binary values: three-digit group is, and 51-digit group is. The character at index zero of the returned string holds the number of digits in the rightmost group. The character at index 1 holds the number of digits in the second group from the right, etc. The grouping indicated by the last character in the returned string is reused to group all remaining digits in the (left part of) the number.

Return value
The object of type std holding the groups. The standard specializations of return an empty string, indicating no grouping. Typical groupings (e.g. the locale) return.