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isgreater(3)            Library Functions Manual            isgreater(3)

ИМЯ

       isgreater, isgreaterequal, isless, islessequal, islessgreater,
       isunordered - floating-point relational tests without exception
       for NaN

БИБЛИОТЕКА

       Math library (libm, -lm)

СИНТАКСИС

       #include <math.h>

       int isgreater(x, y);
       int isgreaterequal(x, y);
       int isless(x, y);
       int islessequal(x, y);
       int islessgreater(x, y);
       int isunordered(x, y);

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

           All functions described here:
               _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

ОПИСАНИЕ

       The normal relational operations (like <, "less than") fail if
       one of the operands is NaN.  This will cause an exception.  To
       avoid this, C99 defines the macros listed below.

       These macros are guaranteed to evaluate their arguments only
       once.  The arguments must be of real floating-point type (note:
       do not pass integer values as arguments to these macros, since
       the arguments will not be promoted to real-floating types).

       isgreater()
              determines (x) > (y) without an exception if x or y is
              NaN.

       isgreaterequal()
              determines (x) >= (y) without an exception if x or y is
              NaN.

       isless()
              determines (x) < (y) without an exception if x or y is
              NaN.

       islessequal()
              determines (x) <= (y) without an exception if x or y is
              NaN.

       islessgreater()
              determines (x) < (y) || (x) > (y) without an exception if
              x or y is NaN.  This macro is not equivalent to x != y
              because that expression is true if x or y is NaN.

       isunordered()
              determines whether its arguments are unordered, that is,
              whether at least one of the arguments is a NaN.

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       The macros other than isunordered() return the result of the
       relational comparison; these macros return 0 if either argument
       is a NaN.

       isunordered() returns 1 if x or y is NaN and 0 otherwise.

ОШИБКИ

       No errors occur.

АТРИБУТЫ

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ isgreater(), isgreaterequal(),      │ Thread safety │ MT-Safe │
       │ isless(), islessequal(),            │               │         │
       │ islessgreater(), isunordered()      │               │         │
       └─────────────────────────────────────┴───────────────┴─────────┘

ВЕРСИИ

       Not all hardware supports these functions, and where hardware
       support isn't provided, they will be emulated by macros.  This
       will result in a performance penalty.  Don't use these functions
       if NaN is of no concern for you.

СТАНДАРТЫ

       C11, POSIX.1-2008.

ИСТОРИЯ

       POSIX.1-2001, C99.

СМОТРИТЕ ТАКЖЕ

       fpclassify(3), isnan(3)

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
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       2024-06-26.  If you discover any rendering problems in this HTML
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       part of the original manual page), send a mail to
       man-pages@man7.org

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

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