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diff --git a/man3p/nextafter.3p b/man3p/nextafter.3p new file mode 100644 index 000000000..881b28dd1 --- /dev/null +++ b/man3p/nextafter.3p @@ -0,0 +1,123 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "NEXTAFTER" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" nextafter +.SH NAME +nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl +\- next representable floating-point +number +.SH SYNOPSIS +.LP +\fB#include <math.h> +.br +.sp +double nextafter(double\fP \fIx\fP\fB, double\fP \fIy\fP\fB); +.br +float nextafterf(float\fP \fIx\fP\fB, float\fP \fIy\fP\fB); +.br +long double nextafterl(long double\fP \fIx\fP\fB, long double\fP \fIy\fP\fB); +.br +double nexttoward(double\fP \fIx\fP\fB, long double\fP \fIy\fP\fB); +.br +float nexttowardf(float\fP \fIx\fP\fB, long double\fP \fIy\fP\fB); +.br +long double nexttowardl(long double\fP \fIx\fP\fB, long double\fP +\fIy\fP\fB); +.br +\fP +.SH DESCRIPTION +.LP +The \fInextafter\fP(), \fInextafterf\fP(), and \fInextafterl\fP() +functions shall compute the next representable +floating-point value following \fIx\fP in the direction of \fIy\fP. +Thus, if \fIy\fP is less than \fIx\fP, \fInextafter\fP() +shall return the largest representable floating-point number less +than \fIx\fP. The \fInextafter\fP(), \fInextafterf\fP(), and +\fInextafterl\fP() functions shall return \fIy\fP if \fIx\fP equals +\fIy\fP. +.LP +The \fInexttoward\fP(), \fInexttowardf\fP(), and \fInexttowardl\fP() +functions shall be equivalent to the corresponding +\fInextafter\fP() functions, except that the second parameter shall +have type \fBlong double\fP and the functions shall return +\fIy\fP converted to the type of the function if \fIx\fP equals \fIy\fP. +.LP +An application wishing to check for error situations should set \fIerrno\fP +to zero and call +\fIfeclearexcept\fP(FE_ALL_EXCEPT) before calling these functions. +On return, if \fIerrno\fP is non-zero or +\fIfetestexcept\fP(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) +is non-zero, an error has occurred. +.SH RETURN VALUE +.LP +Upon successful completion, these functions shall return the next +representable floating-point value following \fIx\fP in the +direction of \fIy\fP. +.LP +If \fIx\fP== \fIy\fP, \fIy\fP (of the type \fIx\fP) shall be returned. +.LP +If \fIx\fP is finite and the correct function value would overflow, +a range error shall occur and \(+-HUGE_VAL, +\(+-HUGE_VALF, and \(+-HUGE_VALL (with the same sign as \fIx\fP) shall +be returned as appropriate for the return type of +the function. +.LP +If +\fIx\fP or \fIy\fP is NaN, a NaN shall be returned. +.LP +If \fIx\fP!= \fIy\fP and the correct function value is subnormal, +zero, or underflows, a range error shall occur, and either +the correct function value (if representable) or 0.0 shall be returned. +.SH ERRORS +.LP +These functions shall fail if: +.TP 7 +Range\ Error +The correct value overflows. +.LP +If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, +then \fIerrno\fP shall be set to [ERANGE]. If the +integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, +then the overflow floating-point exception shall be +raised. +.TP 7 +Range\ Error +The correct value is subnormal or underflows. +.LP +If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, +then \fIerrno\fP shall be set to [ERANGE]. If the +integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, +then the underflow floating-point exception shall be +raised. +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling +& MATH_ERREXCEPT) are independent of +each other, but at least one of them must be non-zero. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIfeclearexcept\fP() , \fIfetestexcept\fP() , the Base +Definitions volume of IEEE\ Std\ 1003.1-2001, Section 4.18, Treatment +of +Error Conditions for Mathematical Functions, \fI<math.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html . |