LROUND(3)                  Linux Programmer's Manual                 LROUND(3)



NAME
       lround,  lroundf, lroundl, llround, llroundf, llroundl - round to near-
       est integer

SYNOPSIS
       #include <math.h>

       long int lround(double x);
       long int lroundf(float x);
       long int lroundl(long double x);

       long long int llround(double x);
       long long int llroundf(float x);
       long long int llroundl(long double x);

       Link with -lm.

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

       All functions shown above:
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

DESCRIPTION
       These functions round their argument  to  the  nearest  integer  value,
       rounding halfway cases away from zero, regardless of the current round-
       ing direction (see fenv(3)).

       Note that unlike the round(3) and ceil(3), functions, the  return  type
       of these functions differs from that of their arguments.

RETURN VALUE
       These functions return the rounded integer value.

       If  x  is a NaN or an infinity, or the rounded value is too large to be
       stored in a long (long long in the case of the ll* functions),  then  a
       domain error occurs, and the return value is unspecified.

ERRORS
       See  math_error(7) for information on how to determine whether an error
       has occurred when calling these functions.

       The following errors can occur:

       Domain error: x is a NaN or infinite, or the rounded value is too large
              An invalid floating-point exception (FE_INVALID) is raised.

       These functions do not set errno.

VERSIONS
       These functions first appeared in glibc in version 2.1.

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       allbox;  lbw33  lb  lb  l  l l.  Interface Attribute Value T{ lround(),
       lroundf(), lroundl(),
       llround(), llroundf(), llroundl() T}   Thread safety  MT-Safe

CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

SEE ALSO
       ceil(3), floor(3), lrint(3), nearbyint(3), rint(3), round(3)

COLOPHON
       This page is part of release 4.16 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.



                                  2017-09-15                         LROUND(3)