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diff --git a/devdocs/c/numeric%2Ffenv%2Ffeexceptflag.html b/devdocs/c/numeric%2Ffenv%2Ffeexceptflag.html new file mode 100644 index 00000000..04da8f88 --- /dev/null +++ b/devdocs/c/numeric%2Ffenv%2Ffeexceptflag.html @@ -0,0 +1,68 @@ + <h1 id="firstHeading" class="firstHeading">fegetexceptflag, fesetexceptflag</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><fenv.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">int fegetexceptflag( fexcept_t* flagp, int excepts );</pre> +</td> <td> (1) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">int fesetexceptflag( const fexcept_t* flagp, int excepts );</pre> +</td> <td> (2) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> </table> <p>1) Attempts to obtain the full contents of the floating-point exception flags that are listed in the bitmask argument <code>excepts</code>, which is a bitwise OR of the <a href="fe_exceptions" title="c/numeric/fenv/FE exceptions">floating-point exception macros</a>.</p> +<p>2) Attempts to copy the full contents of the floating-point exception flags that are listed in <code>excepts</code> from <code>flagp</code> into the floating-point environment. Does not raise any exceptions, only modifies the flags.</p> +<p>The full contents of a floating-point exception flag is not necessarily a boolean value indicating whether the exception is raised or cleared. For example, it may be a struct which includes the boolean status and the address of the code that triggered the exception. These functions obtain all such content and obtain/store it in <code>flagp</code> in implementation-defined format.</p> +<h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> flagp </td> <td> - </td> <td> pointer to an <code>fexcept_t</code> object where the flags will be stored or read from </td> +</tr> <tr class="t-par"> <td> excepts </td> <td> - </td> <td> bitmask listing the exception flags to get/set </td> +</tr> +</table> <h3 id="Return_value"> Return value</h3> <p><code>0</code> on success, non-zero otherwise.</p> +<h3 id="Example"> Example</h3> <div class="t-example"> <div class="c source-c"><pre data-language="c">#include <stdio.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"); +} + +int main(void) +{ + fexcept_t excepts; + + /* Setup a "current" set of exception flags. */ + feraiseexcept(FE_INVALID); + show_fe_exceptions(); + + /* Save current exception flags. */ + fegetexceptflag(&excepts,FE_ALL_EXCEPT); + + /* Temporarily raise two other exceptions. */ + feclearexcept(FE_ALL_EXCEPT); + feraiseexcept(FE_OVERFLOW | FE_INEXACT); + show_fe_exceptions(); + + /* Restore previous exception flags. */ + fesetexceptflag(&excepts,FE_ALL_EXCEPT); + show_fe_exceptions(); + + return 0; +}</pre></div> <p>Output:</p> +<div class="text source-text"><pre data-language="c">current exceptions raised: FE_INVALID +current exceptions raised: FE_INEXACT FE_OVERFLOW +current exceptions raised: FE_INVALID</pre></div> </div> <h3 id="References"> References</h3> <ul> +<li> C11 standard (ISO/IEC 9899:2011): </li> +<ul> +<li> 7.6.2.2 The fegetexceptflag function (p: 210) </li> +<li> 7.6.2.4 The fesetexceptflag function (p: 211) </li> +</ul> +<li> C99 standard (ISO/IEC 9899:1999): </li> +<ul> +<li> 7.6.2.2 The fegetexceptflag function (p: 191) </li> +<li> 7.6.2.4 The fesetexceptflag function (p: 192) </li> +</ul> +</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/numeric/fenv/feexceptflag" title="cpp/numeric/fenv/feexceptflag">C++ documentation</a></span> for <code>fegetexceptflag, fesetexceptflag</code> </td> +</tr> </table> <div class="_attribution"> + <p class="_attribution-p"> + © cppreference.com<br>Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.<br> + <a href="https://en.cppreference.com/w/c/numeric/fenv/feexceptflag" class="_attribution-link">https://en.cppreference.com/w/c/numeric/fenv/feexceptflag</a> + </p> +</div> |