wcstold(3)						     Library Functions Manual							wcstold(3)

NAME

       wcstold - Converts a wide-character string to a long double-precision value

LIBRARY

       Standard C Library (libc)

SYNOPSIS

       #include <wchar.h>

       long double wcstold (	  const wchar_t *ws,	  wchar_t **endptr);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       wcstold():  ISO C

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Points  to  the	wide-character	string	to be converted to a long double-precision floating-point value.  Points to a pointer in which the
       wcstold() function stores the position of the final wide-character segment of the string, which contains unrecognized  characters  and  the
       null terminator.

DESCRIPTION

       The  wcstold() function converts the initial portion of the wide-character string pointed to by the ws parameter to a long double-precision
       floating-point value. The input wide-character string is first broken down into three parts: an initial (possibly empty) sequence of white-
       space  wide-character  codes  (as specified by the iswspace() function); a subject sequence interpreted as a floating-point constant; and a
       final wide-character string of one or more unrecognized wide-character codes, including the terminating null wide  character.  The  subject
       sequence is then (if possible) converted to a floating-point number and returned as the result of the wcstold() function.

       The  subject  sequence is expected to consist of an optional + (plus sign) or - (minus sign), a nonempty sequence of digits (which may con-
       tain a radix character), and an optional exponent. The exponent consists of e or E, followed by an optional sign, followed by one  or  more
       decimal	digits.  The  subject sequence is 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 nonwhite-space wide-character code is
       other than a sign, a digit, or a radix character.

       If the subject sequence is valid, the sequence of wide-character codes, starting with the first digit or radix character (whichever  occurs
       first),	is interpreted as a floating-point or double-precision floating-point constant. The locale's radix character is treated as equiva-
       lent to the . (period) within floating-point constants in the C locale.	If neither an exponent or radix character appears, a radix charac-
       ter is assumed to follow the last digit in the wide-character string. If the subject sequence begins with - ( a minus sign), the conversion
       value is negated.  The radix character is determined by the LC_NUMERIC category in the program's current locale. In the C locale, or  in  a
       locale where the radix character is not defined, the radix character is a . (period).

       The  wcstold()  function  stores a pointer to the final wide-character segment of the string (starting with the first invalid character) in
       the object pointed to by the endptr parameter, unless the endptr parameter is a null pointer.

RETURN VALUES

       The wcstold() function returns the converted value of a long double-precision floating-point value if a valid  floating-point  constant	is
       found.	If  the  converted  value  is outside the range of representable values (either too high or too low), the function returns plus or
       minus HUGE_VAL and sets errno to [ERANGE].  If the converted value would cause underflow, the function returns 0 (zero) and sets  errno	to
       [ERANGE].  If  the  subject sequence is empty or does not have the expected form, the function performs no conversion and returns 0 (zero).
       In this case, the value specified by the ws parameter is stored in the object pointed to by the endptr parameter, provided that the  endptr
       parameter is not a null pointer.

       Since the wcstold() function returns 0 (zero) or HUGE_VAL in the event of an error and these values are also valid returns if the wcstold()
       function is successful, applications should set errno to 0 (zero) before each call to the wcstold() function and  check	errno  after  each
       return  from  the  function.   If  errno is nonzero after a return, an error occurred.  Additionally, if 0 (zero) is returned, applications
       should check if the endptr parameter equals the nptr parameter. In this case, there was no valid subject string.

ERRORS

       If the following condition occurs, the wcstold() function sets errno to the corresponding value: The converted value would cause  underflow
       or, if outside the range of representable values, overflow.

RELATED INFORMATION

       Functions: atof(3), iswspace(3), localeconv(3), scanf(3), setlocale(3), wcstod(3), wcstol(3)

       Standards: standards(5) delim off

																	wcstold(3)