overby.me
this repo has no description
1.\" Copyright (c) 1985, 1991 Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\" notice, this list of conditions and the following disclaimer in the
11.\" documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\" must display the following acknowledgement:
14.\" This product includes software developed by the University of
15.\" California, Berkeley and its contributors.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\" may be used to endorse or promote products derived from this software
18.\" without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\" from: @(#)rint.3 5.1 (Berkeley) 5/2/91
33.\" $Id: round.3,v 1.4 2004/12/20 21:35:46 scp Exp $
34.\"
35.Dd July 02, 2008
36.Dt ROUND 3
37.Os
38.Sh NAME
39.Nm round ,
40.Nm lround ,
41.Nm llround
42.Nd round to integral value, regardless of rounding direction
43.Sh SYNOPSIS
44.Fd #include <math.h>
45.Ft double
46.Fn round "double x"
47.Ft long double
48.Fn roundl "long double x"
49.Ft float
50.Fn roundf "float x"
51.Ft long int
52.Fn lround "double x"
53.Ft long int
54.Fn lroundl "long double x"
55.Ft long int
56.Fn lroundf "float x"
57.Ft long long int
58.Fn llround "double x"
59.Ft long long int
60.Fn llroundl "long double x"
61.Ft long long int
62.Fn llroundf "float x"
63.Sh DESCRIPTION
64The
65.Fn round
66functions return the integral value
67nearest to
68.Fa x
69rounding half-way cases away from zero, regardless of the current rounding direction.
70.Pp
71The
72.Fn lround
73and
74.Fn llround
75functions return the integral value nearest to
76.Fa x
77(rounding half-way cases away from zero, regardless of the current rounding direction) in the return formats specified. If the rounded
78value is outside the range of the return type, the numeric result is unspecified and the
79"invalid" floating-point exception is raised. A range error may occur if the magnitude of
80.Fa x
81is too large.
82.Sh SPECIAL VALUES
83.Fn round "�0"
84returns �0.
85.Pp
86.Fn round "�infinity"
87returns �infinity.
88.Pp
89The
90.Fn round
91functions may, but are not required to, raise the "inexact" floating-point exception for non-integer numeric arguments.
92.Pp
93The
94.Fn lround
95and
96.Fn llround
97functions need not raise the "inexact" floating-point exception for non-integer arguments that round to within the range of the return type.
98.Sh NOTE
99The
100.Fn roundtol
101function is deprecated. Please use the C99 function
102.Fn lround
103instead.
104.Sh SEE ALSO
105.Xr abs 3 ,
106.Xr fabs 3 ,
107.Xr ceil 3 ,
108.Xr floor 3 ,
109.Xr math 3 ,
110.Xr rint 3
111.Sh STANDARDS
112The
113.Fn round
114,
115.Fn lround
116, and
117.Fn llround
118functions conform to ISO/IEC 9899:1999(E).