rm_/lib/c-strtod.h
2020-09-02 16:47:03 +08:00

46 lines
1.9 KiB
C

/* Convert string to double, using the C locale. -*- coding: utf-8 -*-
Copyright (C) 2003-2004, 2009-2020 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#ifdef __cplusplus
extern "C" {
#endif
/* Parse the initial portion of the string pointed to by NPTR as a floating-
point number (in decimal or hexadecimal notation), like in the C locale:
accepting only the ASCII digits '0'..'9', and only '.' as decimal point
character.
If ENDPTR is not NULL, set *ENDPTR to point to the first byte beyond the
parsed number or to NPTR if the string does not start with a parsable
number.
Return value:
- If successful, return the value as a double or 'long double',
respectively, and don't modify errno.
- In case of overflow, return ±HUGE_VAL or ±HUGE_VALL, respectively, and
set errno to ERANGE.
- In case of underflow, return a value very near to 0 and set errno to
ERANGE.
- If the string does not start with a number at all, return 0 (and recall
that if ENDPTR != NULL, *ENDPTR is set to NPTR), and maybe set errno to
EINVAL.
- In case of other error, return 0 and set errno, for example to ENOMEM. */
extern double c_strtod (char const *nptr, char **endptr);
extern long double c_strtold (char const *nptr, char **endptr);
#ifdef __cplusplus
}
#endif