double wcstod(const wchar_t *nptr, wchar_t **endptr);
double wstod(const wchar_t *nptr, wchar_t **endptr);
double watof(wchar_t *nptr);
The expected form of the subject sequence is an optional `+' or `-' sign, then a non-empty sequence of digits optionally containing a radix, then an optional exponent part. An exponent part consists of `e' or `E', followed by an optional sign, followed by one or more decimal digits. The subject sequence is defined as the longest initial subsequence of the input wide character string, starting with the first non-white-space wide-character code, that is of the expected form. The subject sequence contains no wide-character codes if the input wide character string is empty or consists entirely of white-space wide-character codes, or if the first wide-character code that is not white space other than a sign, a digit or a radix.
If the subject sequence has the expected form, the sequence of wide-character codes starting with the first digit or the radix (whichever occurs first) is interpreted as a floating constant as defined in the C language, except that the radix is used in place of a period, and that if neither an exponent part nor a radix appears, a radix is assumed to follow the last digit in the wide character string. If the subject sequence begins with a minus sign (-), the value resulting from the conversion is negated. A pointer to the final wide character string is stored in the object pointed to by endptr, provided that endptr is not a null pointer.
The radix is defined in the program's locale (category LC_NUMERIC). In the POSIX locale, or in a locale where the radix is not defined, the radix defaults to a period (.).
In other than the POSIX locale, other implementation-dependent subject sequence forms may be accepted.
If the subject sequence is empty or does not have the expected form, no conversion is performed; the value of nptr is stored in the object pointed to by endptr, provided that endptr is not a null pointer.
watof(str) is equivalent to wstod(str, (wchar_t **)NULL).
If the correct value is outside the range of representable values, ±HUGE_VAL is returned (according to the sign of the value), and errno is set to ERANGE.
If the correct value would cause underflow, 0 is returned, and errno is set to ERANGE.
wcstod() and wcstod() may fail if:
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97