From 82ba818ff456bcd6d56a06226e3f27e98fbb55c3 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Thu, 14 Aug 2025 22:58:58 -0500 Subject: removing all downloaded devdocs files --- devdocs/c/numeric%2Ffenv%2Ffeenv.html | 116 ---------------------------------- 1 file changed, 116 deletions(-) delete mode 100644 devdocs/c/numeric%2Ffenv%2Ffeenv.html (limited to 'devdocs/c/numeric%2Ffenv%2Ffeenv.html') diff --git a/devdocs/c/numeric%2Ffenv%2Ffeenv.html b/devdocs/c/numeric%2Ffenv%2Ffeenv.html deleted file mode 100644 index 55c9bb86..00000000 --- a/devdocs/c/numeric%2Ffenv%2Ffeenv.html +++ /dev/null @@ -1,116 +0,0 @@ -

fegetenv, fesetenv

Defined in header <fenv.h> 
int fegetenv( fenv_t* envp );
-		 (1) (since C99) 
int fesetenv( const fenv_t* envp );
-		 (2) (since C99)

1) Attempts to store the status of the floating-point environment in the object pointed to by envp.

-

2) Attempts to establish the floating-point environment from the object pointed to by envp. The value of that object must be previously obtained by a call to feholdexcept or fegetenv or be a floating-point macro constant. If any of the floating-point status flags are set in envp, they become set in the environment (and are then testable with fetestexcept), but the corresponding floating-point exceptions are not raised (execution continues uninterrupted)

-

Parameters

- -
envp - pointer to the object of type fenv_t which holds the status of the floating-point environment

Return value

​0​ on success, non-zero otherwise.

-

Example

#include <stdio.h>
-#include <math.h>
-#include <fenv.h>
- 
-#pragma STDC FENV_ACCESS ON
- 
-void show_fe_exceptions(void)
-{
-    printf("current exceptions raised: ");
-    if(fetestexcept(FE_DIVBYZERO))     printf(" FE_DIVBYZERO");
-    if(fetestexcept(FE_INEXACT))       printf(" FE_INEXACT");
-    if(fetestexcept(FE_INVALID))       printf(" FE_INVALID");
-    if(fetestexcept(FE_OVERFLOW))      printf(" FE_OVERFLOW");
-    if(fetestexcept(FE_UNDERFLOW))     printf(" FE_UNDERFLOW");
-    if(fetestexcept(FE_ALL_EXCEPT)==0) printf(" none");
-    printf("\n");
-}
- 
-void show_fe_rounding_method(void)
-{
-    printf("current rounding method:    ");
-    switch (fegetround()) {
-           case FE_TONEAREST:  printf ("FE_TONEAREST");  break;
-           case FE_DOWNWARD:   printf ("FE_DOWNWARD");   break;
-           case FE_UPWARD:     printf ("FE_UPWARD");     break;
-           case FE_TOWARDZERO: printf ("FE_TOWARDZERO"); break;
-           default:            printf ("unknown");
-    };
-    printf("\n");
-}
- 
-void show_fe_environment(void)
-{
-    show_fe_exceptions();
-    show_fe_rounding_method();
-}    
- 
-int main(void)
-{
-    fenv_t curr_env;
-    int rtn;
- 
-    /* Show default environment. */
-    show_fe_environment();
-    printf("\n");
- 
-    /* Perform some computation under default environment. */
-    printf("+11.5 -> %+4.1f\n", rint(+11.5)); /* midway between two integers */
-    printf("+12.5 -> %+4.1f\n", rint(+12.5)); /* midway between two integers */
-    show_fe_environment();
-    printf("\n");
- 
-    /* Save current environment. */
-    rtn = fegetenv(&curr_env);
- 
-    /* Perform some computation with new rounding method. */
-    feclearexcept(FE_ALL_EXCEPT);
-    fesetround(FE_DOWNWARD);
-    printf("1.0/0.0 = %f\n", 1.0/0.0);
-    printf("+11.5 -> %+4.1f\n", rint(+11.5));
-    printf("+12.5 -> %+4.1f\n", rint(+12.5));
-    show_fe_environment();
-    printf("\n");
- 
-    /* Restore previous environment. */
-    rtn = fesetenv(&curr_env);
-    show_fe_environment();
- 
-    return 0;
-}

Output:

-
current exceptions raised: none
-current rounding method:   FE_TONEAREST
- 
-+11.5 -> +12.0
-+12.5 -> +12.0
-current exceptions raised: FE_INEXACT
-current rounding method:   FE_TONEAREST
- 
-1.0/0.0 = inf
-+11.5 -> +11.0
-+12.5 -> +12.0
-current exceptions raised: FE_DIVBYZERO FE_INEXACT
-current rounding method:   FE_DOWNWARD
- 
-current exceptions raised: FE_INEXACT
-current rounding method:   FE_TONEAREST

References

See also

- - - -
-
(C99)
 saves the environment, clears all status flags and ignores all future errors
(function)
-
(C99)
 restores the floating-point environment and raises the previously raise exceptions
(function)
-
(C99)
 default floating-point environment
(macro constant)
C++ documentation for fegetenv, fesetenv
-

- © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
- https://en.cppreference.com/w/c/numeric/fenv/feenv -

-
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