LRINT(3)                   POSIX Programmer's Manual                  LRINT(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.


NNAAMMEE
       lrint, lrintf, lrintl -- round to nearest integer value using current
       rounding direction

SSYYNNOOPPSSIISS
       #include <math.h>

       long lrint(double _x);
       long lrintf(float _x);
       long lrintl(long double _x);

DDEESSCCRRIIPPTTIIOONN
       The functionality described on this reference page is aligned with the
       ISO C standard. Any conflict between the requirements described here
       and the ISO C standard is unintentional. This volume of POSIX.1-2008
       defers to the ISO C standard.

       These functions shall round their argument to the nearest integer
       value, rounding according to the current rounding direction.

       An application wishing to check for error situations should set _e_r_r_n_o
       to zero and call _f_e_c_l_e_a_r_e_x_c_e_p_t(FE_ALL_EXCEPT) before calling these
       functions. On return, if _e_r_r_n_o is non-zero or _f_e_t_e_s_t_e_x_c_e_p_t(FE_INVALID |
       FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has
       occurred.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, these functions shall return the rounded
       integer value.

       If _x is NaN, a domain error shall occur and an unspecified value is
       returned.

       If _x is +Inf, a domain error shall occur and an unspecified value is
       returned.

       If _x is -Inf, a domain error shall occur and an unspecified value is
       returned.

       If the correct value is positive and too large to represent as a lloonngg,
       an unspecified value shall be returned.  On systems that support the
       IEC 60559 Floating-Point option, a domain error shall occur; otherwise,
       a domain error may occur.

       If the correct value is negative and too large to represent as a lloonngg,
       an unspecified value shall be returned.  On systems that support the
       IEC 60559 Floating-Point option, a domain error shall occur; otherwise,
       a domain error may occur.

EERRRROORRSS
       These functions shall fail if:

       Domain Error
                   The _x argument is NaN or +-Inf, or the correct value is not
                   representable as an integer.

                   If the integer expression (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERRNO)
                   is non-zero, then _e_r_r_n_o shall be set to [[EEDDOOMM]].  If the
                   integer expression (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERREXCEPT) is
                   non-zero, then the invalid floating-point exception shall
                   be raised.

       These functions may fail if:

       Domain Error
                   The correct value is not representable as an integer.

                   If the integer expression (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERRNO)
                   is non-zero, then _e_r_r_n_o shall be set to [[EEDDOOMM]].  If the
                   integer expression (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERREXCEPT) is
                   non-zero, then the invalid floating-point exception shall
                   be raised.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       On error, the expressions (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERRNO) and
       (_m_a_t_h___e_r_r_h_a_n_d_l_i_n_g & MATH_ERREXCEPT) are independent of each other, but
       at least one of them must be non-zero.

RRAATTIIOONNAALLEE
       These functions provide floating-to-integer conversions. They round
       according to the current rounding direction. If the rounded value is
       outside the range of the return type, the numeric result is unspecified
       and the invalid floating-point exception is raised. When they raise no
       other floating-point exception and the result differs from the
       argument, they raise the inexact floating-point exception.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _f_e_c_l_e_a_r_e_x_c_e_p_t(), _f_e_t_e_s_t_e_x_c_e_p_t(), _l_l_r_i_n_t()

       The Base Definitions volume of POSIX.1-2008, _S_e_c_t_i_o_n _4_._1_9, _T_r_e_a_t_m_e_n_t _o_f
       _E_r_r_o_r _C_o_n_d_i_t_i_o_n_s _f_o_r _M_a_t_h_e_m_a_t_i_c_a_l _F_u_n_c_t_i_o_n_s, <<mmaatthh..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be obtained online
       at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2013                             LRINT(3)
