Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
std::feclearexcept(3)	      C++ Standard Libary	 std::feclearexcept(3)

NAME
       std::feclearexcept - std::feclearexcept

Synopsis
	  Defined in header <cfenv>
	  int feclearexcept( int excepts );  (since C++11)

	  Attempts  to	clear the floating-point exceptions that are listed in
       the bitmask
	  argument excepts, which is a bitwise OR of the floating point	excep-
       tion macros.

Parameters
	  excepts - bitmask listing the	exception flags	to clear

Return value
	  0 if all indicated exceptions	were successfully cleared  or  if  ex-
       cepts is	zero.
	  Returns a non-zero value on error.

Example
       // Run this code

	#include <iostream>
	#include <cfenv>
	#include <cmath>

	#pragma	STDC FENV_ACCESS ON

	volatile  double  zero = 0.0; // volatile not needed where FENV_ACCESS
       is supported
	volatile double	one = 1.0;  // volatile	not needed  where  FENV_ACCESS
       is supported

	int main()
	{
	    std::feclearexcept(FE_ALL_EXCEPT);
	    std::cout <<  "1.0/0.0 = " << 1.0 /	zero <<	'\n';
	    if(std::fetestexcept(FE_DIVBYZERO))	{
		std::cout << "division by zero reported\n";
	    } else {
		std::cout << "divsion by zero not reported\n";
	    }

	    std::feclearexcept(FE_ALL_EXCEPT);
	    std::cout << "1.0/10 = " <<	one/10 << '\n';
	    if(std::fetestexcept(FE_INEXACT)) {
		std::cout << "inexact result reported\n";
	    } else {
		std::cout << "inexact result not reported\n";
	    }

	    std::feclearexcept(FE_ALL_EXCEPT);
	    std::cout << "sqrt(-1) = " << std::sqrt(-1)	<< '\n';
	    if(std::fetestexcept(FE_INVALID)) {
		std::cout << "invalid result reported\n";
	    } else {
		std::cout << "invalid result not reported\n";
	    }
	}

Output:
	1.0/0.0	= inf
	division by zero reported
	1.0/10 = 0.1
	inexact	result reported
	sqrt(-1) = -nan
	invalid	result reported

See also
	  fetestexcept determines which	of the specified floating-point	status
       flags are set
	  (C++11)      (function)

http://cppreference.com		  2022.07.31		 std::feclearexcept(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=std::feclearexcept&sektion=3&manpath=FreeBSD+Ports+15.0>

home | help