Interpret characters from the half-open iterator range denoted by the specified begin and end, generate a decimal floating-point number and store it into the specified value. During conversion the formatting flags of the specified str (str.flags()) are obeyed; character classifications are determined by the bsl::ctype while punctuation characters are determined by the bsl::numpunct facet imbued to the str stream-base. Use the specified err to report back failure or EOF streams states. For further, more detailed information please consult the section [lib.facet.num.get.virtuals]of the C++ Standard. Note that for the conversions to the Decimal32, 64 and 128 types the conversion specifiers are %Hg, %Dg and %DDg, respectively. Also note that these (possibly overridden) do_get virtual function are used by every formatted C++ stream input operator call (in >> aDecNumber).