All functions named
from_chars
analyze the string [
first, last)
for a pattern,
where [
first, last) is required to be a valid range
.If no characters match the pattern,
value is unmodified,
the member
ptr of the return value is
first and
the member
ec is equal to
errc::invalid_argument.[
Note 1:
If the pattern allows for an optional sign,
but the string has no digit characters following the sign,
no characters match the pattern
. —
end note]
Otherwise,
the characters matching the pattern
are interpreted as a representation
of a value of the type of
value.The member
ptr
of the return value
points to the first character
not matching the pattern,
or has the value
last
if all characters match
.If the parsed value
is not in the range
representable by the type of
value,
value is unmodified and
the member
ec of the return value
is equal to
errc::result_out_of_range.Otherwise,
value is set to the parsed value,
after rounding according to
round_to_nearest, and
the member
ec is value-initialized
.