The next element of
fmt is equal to
'%',
optionally followed by a modifier character,
followed by a conversion specifier character,
format,
together forming a conversion specification
valid for the POSIX function
strptime. If the number of elements in the range [
fmt, fmtend)
is not sufficient to unambiguously determine
whether the conversion specification is complete and valid,
the function evaluates
err = ios_base::failbit. Otherwise,
the function evaluates
s = do_get(s, end, f, err, t, format, modifier),
where the value of
modifier is
'\0'
when the optional modifier is absent from the conversion specification
. If
err == ios_base::goodbit holds
after the evaluation of the expression,
the function increments
fmt
to point just past the end of the conversion specification and
continues looping
.