C in a Nutshell

Name

wcstod, wcstof, wcstold

Synopsis

Converts a wide string into a floating-point number

#include <wchar.h>
doublewcstod( const wchar_t * restrict wcs, wchar_t ** restrict endptr );
float wcstof( const wchar_t * restrict wcs,
              wchar_t ** restrict endptr );        (C99)
long double wcstold( const wchar_t * restrict wcs,
                     wchar_t ** restrict endptr );        (C99)

The wcstod() function attempts to interpret the wide string addressed by its first pointer argument, wcs, as a floating-point numeric value, and returns the result with the type double. wcstof() and wcsold() are similar, but return float and long double respectively. Leading whitespace wide characters are ignored, and the string converted ends with the last wide character that can be interpreted as part of a floating-point numeral. The second parameter, endptr, is a pointer to a pointer. If its argument value is not a null pointer, then the function stores a pointer to the first wide character that is not part of the numeral converted in the location addressed by the endptr argument. (The locations that the function reads from and writes to using its restricted pointer parameters must not overlap.) If no conversion is possible, the function returns 0.

If the resulting value exceeds the range of the function’s type, then the return value is positive or negative HUGE_VAL (or HUGE_VALF or HUGE_VALL, for the float and long double variants). On an overflow, the errno variable is set to the value of ERANGE (“range error”). If the conversion produces ...