nan.3   [plain text]


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.\"     from: @(#)floor.3	6.5 (Berkeley) 4/19/91
.\"	$Id: nan.3,v 1.5 2004/12/20 21:35:46 scp Exp $
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.Dd July 24, 2003
.Dt NAN 3
.Os
.Sh NAME
.Nm nan
.Nd generate a quiet NaN
.Sh SYNOPSIS
.Fd #include <math.h>
.Ft double
.Fn nan "const char *tagp"
.Ft long double
.Fn nanl "const char *tagp"
.Ft float
.Fn nanf "const char *tagp"
.Sh DESCRIPTION
The
.Fn nan
functions return a quiet NaN. The character string 
.Fa tagp
is converted to an integer, which is clipped
to the range 0 to 255, inclusive. This value is used as the NaN code. The NaN code is placed
in the 8th through 15th most significant bits of the fraction field of the resulting NaN.   
.Sh SPECIAL VALUES
If
.Fa tagp
is empty, 0 is used for the NaN code.
.Sh STANDARDS
The
.Fn nan
functions conform to ISO/IEC 9899:1999(E).