FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW, FE_UNDERFLOW, FE_ALL_EXCEPT
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definiert in Header <cfenv> | ||
#define FE_DIVBYZERO /*implementation defined power of 2*/ | (seit C++11) | |
#define FE_INEXACT /*implementation defined power of 2*/ | (seit C++11) | |
#define FE_INVALID /*implementation defined power of 2*/ | (seit C++11) | |
#define FE_OVERFLOW /*implementation defined power of 2*/ | (seit C++11) | |
#define FE_UNDERFLOW /*implementation defined power of 2*/ | (seit C++11) | |
#define FE_ALL_EXCEPT FE_DIVBYZERO | FE_INEXACT | \ FE_INVALID | FE_OVERFLOW | \ | (seit C++11) | |
All diese Makro-Konstanten (außer FE_ALL_EXCEPT) auf ganzzahlige konstante Ausdrücke, die verschiedenen Potenzen von 2, die eindeutig zu identifizieren alle unterstützten Gleitkomma-Ausnahmen sind zu erweitern. Jedes Makro wird nur definiert, wenn sie unterstützt wird .
Original:
All these macro constants (except FE_ALL_EXCEPT) expand to integer constant expressions that are distinct powers of 2, which uniquely identify all supported floating-point exceptions. Each macro is only defined if it is supported.
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Die Makro konstanten FE_ALL_EXCEPT, die der bitweisen ODER aller anderen
FE_* ausdehnt, wird immer definiert und ist Null, wenn Gleitkomma-Ausnahmen nicht durch die Implementierung unterstützt werden .Original:
The macro constant FE_ALL_EXCEPT, which expands to the bitwise OR of all other
FE_*, is always defined and is zero if floating-point exceptions are not supported by the implementation.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Constant Original: Constant The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | Explanation |
FE_DIVBYZERO | Division durch Null aufgetreten während der früheren Floating-Point-Betrieb Original: division by zero occurred during the earlier floating-point operation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
FE_INEXACT | ungenauen Ergebnis: Rundung war notwendig, um das Ergebnis der früheren Gleitkommaoperation speichern Original: inexact result: rounding was necessary to store the result of the earlier floating-point operation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
FE_INVALID | ungültige Operation: je früher Floating-Point-Operation konnte nicht ausgeführt Original: invalid operation: the earlier floating-point operation could not performed The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
FE_OVERFLOW | das Ergebnis des früheren Gleitkomma-Operation war zu groß, um darstellbar sein Original: the result of the earlier floating-point operation was too large to be representable The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
FE_UNDERFLOW | das Ergebnis des früheren Gleitkomma-Operation war subnormal Original: the result of the earlier floating-point operation was subnormal The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
FE_ALL_EXCEPT | ODER-Verknüpfung aller unterstützten Fließkomma-Ausnahmen Original: bitwise OR of all supported floating-point exceptions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Die Implementierung kann zusätzliche Makro-Konstanten in
<cfenv> definieren, um zusätzliche Floating-Point-Ausnahmen zu ermitteln. Alle solche Konstanten beginnen mit FE_ von mindestens einem Großbuchstaben gefolgt .Original:
The implementation may define additional macro constants in
<cfenv> to identify additional floating-point exceptions. All such constants begin with FE_ followed by at least one uppercase letter.The text has been machine-translated via Google Translate.
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[Bearbeiten]Beispiel
#include <iostream>#include <cfenv>#include <cmath> #pragma STDC FENV_ACCESS ON volatiledouble zero =0.0;// volatile not needed where FENV_ACCESS is supportedvolatiledouble 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
[Bearbeiten]Siehe auch
(C++11) (C++11) (C++11) | definiert die Fehlerbehandlung durch die üblichen mathematischen Funktionen verwendet Original: defines the error handling mechanism used by the common mathematical functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Makro konstant) |
