nan(3) — Справочная страница Linux

nan(3)                  Library Functions Manual                  nan(3)

ИМЯ

       nan, nanf, nanl - return 'Not a Number'

БИБЛИОТЕКА

       Math library (libm, -lm)

СИНТАКСИС

       #include <math.h>

       double nan(const char *tagp);
       float nanf(const char *tagp);
       long double nanl(const char *tagp);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       nan(), nanf(), nanl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

ОПИСАНИЕ

       These functions return a representation (determined by tagp) of a
       quiet NaN.  If the implementation does not support quiet NaNs,
       these functions return zero.

       The call nan("char-sequence") is equivalent to:

           strtod("NAN(char-sequence)", NULL);

       Similarly, calls to nanf() and nanl() are equivalent to analogous
       calls to strtof(3) and strtold(3).

       The argument tagp is used in an unspecified manner.  On IEEE 754
       systems, there are many representations of NaN, and tagp selects
       one.  On other systems it may do nothing.

АТРИБУТЫ

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────┬───────────────┬────────────────┐
       │ Interface                    │ Attribute     │ Value          │
       ├──────────────────────────────┼───────────────┼────────────────┤
       │ nan(), nanf(), nanl()        │ Thread safety │ MT-Safe locale │
       └──────────────────────────────┴───────────────┴────────────────┘

СТАНДАРТЫ

       C11, POSIX.1-2008.

       See also IEC 559 and the appendix with recommended functions in
       IEEE 754/IEEE 854.

ИСТОРИЯ

       glibc 2.1.  C99, POSIX.1-2001.

СМОТРИТЕ ТАКЖЕ

       isnan(3), strtod(3), math_error(7)

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                         nan(3)

Страницы, которые ссылаются на эту страницу: strtod(3), math_error(7)