NAME

       lround, lroundf, lroundl, llround, llroundf, llroundl - round to nearest integer

SYNOPSIS

       #include <math.h>

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

       long long llround(double x);
       long long llroundf(float x);
       long long 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 rounding 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).
       ┌───────────────────────────────────┬───────────────┬─────────┐
       │ Interface                         │ Attribute     │ Value   │
       ├───────────────────────────────────┼───────────────┼─────────┤
       │ lround(), lroundf(), lroundl(),   │ Thread safety │ MT-Safe │
       │ llround(), llroundf(), llroundl() │               │         │
       └───────────────────────────────────┴───────────────┴─────────┘

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 5.10 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/.

                                                   2020-11-01                                          LROUND(3)