NAME

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

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       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)